- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Adaptive backstepping approach for dc-side controllers of Z-source inverters in grid-tied PV system applications
摘要： Z-source inverters (ZSIs) are single-stage power converters with both voltage buck and boost capabilities provided by the unique impedance network and the ability to operate during shoot-through states. This study proposes a novel non-linear adaptive backstepping method for dc-side controllers in a multi-loop control scheme of the ZSI in grid-tied photovoltaic (PV) systems. Despite the variability of the capacitor and inductor values in the ZSI impedance network, the proposed controller guarantees robust and stable operation under varying levels of PV irradiance and temperature. The shoot-through duty ratio of the ZSI is obtained directly from the output of an MPPT algorithm and the measured PV and inductor currents. This strategy overcomes the disadvantages of the conventional approach such as the non-minimum phase at the dc side of the ZSI. It also eliminates the need to linearise the voltage/current characteristics of the PV arrays and ZSI model. The ac-side controllers consist of an outer proportional–integral voltage controller and an inner deadbeat current controller to achieve unity power factor and stable capacitor voltage in spite of grid voltage fluctuations. The efficacy of the proposed adaptive backstepping controller and the multi-loop control scheme is validated by offline and hardware-in-the-loop real-time simulations.
关键词： maximum power point tracking,Z-source inverters,adaptive backstepping control,grid-tied inverters,photovoltaic systems
更新于2025-09-23 15:21:01
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Adaptive Voltage Regulation for Solar Power Inverters on Distribution Systems
摘要： By means of time-series power flow, this paper compares the performance of several reactive power control modes allowed in the new IEEE 1547. It is shown that voltage-reactive power mode (sometimes called volt-var) should be considered for a universal default setting, with no deadband, the highest allowed gain of 22 for Category B inverters, and a gain of 12.5 for Category A inverters. The reference voltage should adapt to the system voltage, with a 300s time constant.
关键词： Photovoltaic systems,smart grids,inverters,automatic voltage control,distributed power generation
更新于2025-09-23 15:21:01
-
A hybrid output multiport converter for standalone loads and photovoltaic array integration
摘要： Multiport converters (MPCs) are relatively recent power converter structures, which bestow the merits such as the omission of redundant power stages, centralized control, compact packaging, enhanced efficiency, improved reliability, and so on and have larger potential in domestic applications. They have the ability to amalgamate energy sources such as photovoltaic (PV) sources and battery storages, and can accommodate hybrid (ac and dc) domestic loads (bulbs, fans, induction stoves, and electric bike chargers). Hence, they can replace the conventional off-line uninterruptible power supplies, which are habitually used in domestic applications. The unique feature of MPCs is the ability to transfer the power between multiple sources and loads concurrently/independently. This article proposes cascaded sources switched tapping multi-level DC-link inverter (CSSTMLDCLI) involved hybrid loads MPC, which can integrate PV sources and feed above mentioned hybrid domestic loads. The involved novel seven level multilevel inverter structure, the CSSTMLDCLI has reduced component count to offer a high quality ac output, while the dc output is synthesized by a forward converter structure. The working principle of the CSSTMLDCLI along with the systematic design procedure is presented. The validity and effectiveness of the proposed converter are ratified through both MATLAB? Simulink R2016a simulation and the experimentation for a typical solar, battery, and grid supported domestic power backup. The system is managed for a lesser energy purchase using a developed minimal grid usage energy management system, which is implemented using ALTERA QUARTUS II 12.0SP2, field-programmable gate array processor.
关键词： hybrid load MPC (HLMPC),photovoltaic (PV),cascaded sources switched tapping multilevel DC-link inverter (CSSTMLDCLI),multilevel inverters (MLI),pulse width modulation (PWM),multiport converters (MPC)
更新于2025-09-23 15:21:01
-
[IEEE 2019 19th International Conference on Control, Automation and Systems (ICCAS) - Jeju, Korea (South) (2019.10.15-2019.10.18)] 2019 19th International Conference on Control, Automation and Systems (ICCAS) - A Portable Functional Near-Infrared Spectroscopy System Using 4-wavelength LEDs
摘要： Class EF and Class E/F inverters are hybrid inverters that combine the improved switch voltage and current waveforms of Class F and Class F-1 inverters with the ef?cient switching of Class E inverters. As a result, their ef?ciency, output power and power output capability can be higher in some cases than the Class E inverter. Little is known about these inverters and no attempt has been made to provide an in depth analysis on their performance. The design equations that have been previously derived are limited and are only applicable under certain assumptions. This paper is the ?rst to provide a comprehensive set of analytical analysis of Class EF and Class E/F inverters. The Class EF2 inverter is then studied in further detail and three special operation cases are de?ned that allow it to either operate at maximum power-output capability, maximum switching frequency, or maximum output power. Final design equations are provided to allow for rapid design and development. Experimental results are provided to con?rm the accuracy of the performed analysis based on a 23-W Class EF2 inverter at 6.78-MHz and 8.60-MHz switching frequencies. The results also show that the Class EF2 inverter achieved an ef?ciency of 91% compared to a 88% ef?ciency when operated as a Class E inverter.
关键词： high-frequency inverters,Class EF inverters,Class E inverters
更新于2025-09-23 15:19:57
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Study of Open-Circuit Voltage in CdTe/MgCdTe Double-Heterostructure Solar Cells with Different Hole Contacts
摘要： Model predictive control (MPC) has been widely advocated as a design strategy for many aspects of industrial electronics. The methodology has been strongly promoted by some researchers but has also attracted criticism from others. In this context, the purpose of this paper is twofold. First, we show that many existing and popular control strategies, including finite set MPC and linear controllers [proportional integral, proportional resonant (PR)], can be viewed as special cases of MPC. Second, we show that the predictive control framework allows one to embellish these classical control architectures with novel features and to design new and advanced control architectures to address various challenges posed by power electronics applications. The findings of the paper are supported by a practical example of designing of a novel form of PR controller with superior tracking performance and delay compensation, confirmed via simulation and experiments.
关键词： model predictive control (MPC),Control design,dc–ac power converters,pulsewidth modulation inverters,current control
更新于2025-09-23 15:19:57
-
Communication Compact CRLH Leaky-wave Antenna using TE20 Mode Substrate Integrated Waveguide for Broad Space Radiation Coverage
摘要： This paper introduces a combinational modulation method to be used in classic full-bridge single phase inverters. The proposed method eliminates even-order harmonics at the pulse width modulation (PWM) stage in the control section, unlike the conventional method of even order harmonic cancelation in the power stage, and offers a cost-effective design by switching one leg at high frequency. Using a low-cost digital signal controller platform, a regular sampling technique based on real-time calculation was employed to verify the feasibility of the proposed method on a 500-W single phase voltage source inverter. Performance characteristics, such as switching losses and harmonic distortions, are presented for the new approach and compared with a classic inverter modulation method.
关键词： switching frequency,Combinational logic circuits,inverters,pulse width modulation (PWM),silicon carbide,harmonic distortion
更新于2025-09-23 15:19:57
-
[IEEE 2018 International Conference on Smart Grid and Clean Energy Technologies (ICSGCE) - Sg. Long, Cheras, Kajang, Malaysia (2018.5.29-2018.6.1)] 2018 International Conference on Smart Grid and Clean Energy Technologies (ICSGCE) - A Novel Five-Level Inverter Topology with Reactive Power Control for Grid-Connected PV System
摘要： These days multilevel inverters are more popular for grid-connected photovoltaic (PV) systems due to their low cost and high efficiency, as they effectively reduce total harmonic distortion (THD) and electromagnetic interference which results leakage current. Traditional multi-level inverters can only inject real power that cannot provide quality output power. A new international standard VDE-AR-N4105 states that for a grid tied inverter of power rating below 3.68kVA, a power factor (PF) of 0.95 leading to 0.95 lagging should be achieved. So, in this paper the proposed five-level inverter topology for grid-tie PV is controlled using a reactive power control method that ensures higher efficiency while enhancing the stability of the system. The proposed closed loop reactive power control technique additionally provides the ability to inject reactive power into the system. In this proposed topology the reactive power flow standard of operation is explained in details in relation to the proposed multi-level inverter topology. To validate the accuracy of the theoretical analysis, the control technique was applied to the existing multi-level inverter topology and then has been simulated in MATLAB/Simulink software. Comparisons were done on the basis of using and not using PLL for the existing multilevel topology and it is found that, synchronization is achieved with current and voltage if PLL is used, as a result PF is maintained close to unity whereas without PLL the PF decreases. Moreover the five-level output provides a much better output and better PF then other existing topologies.
关键词： phase-locked loop (PLL),multi-level inverters,solar PV,reactive power control
更新于2025-09-23 15:19:57
-
[IEEE 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA) - Brasov, Romania (2019.11.3-2019.11.6)] 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA) - An Optimized Decentralized Control Strategy of Grid-Connected Residential Photovoltaic Inverters Based on Voltage Sensitivity Matrix
摘要： Due to the mismatch between the residential electrical load and the output power of the rooftop photovoltaic (PV) systems, node voltages in a low voltage distribution network (LVDN) may exceed the allowable upper limit during the daytime and drop far below the lower limit at night. Existing LVDN voltage regulation methods based on reactive power control of the rooftop PV inverter usually regulate all the inverters using the same control strategy with identical control parameters, although PV inverters at different nodes have different voltage sensitivities to active and reactive power flows. In this paper, an optimized decentralized control strategy of residential PV inverters based on voltage sensitivity matrix is proposed, and different control parameters would be determined and applied to each PV inverters at different LVDN nodes. The proposed strategy provides an optimal control framework for the rooftop PV inverters to maintain voltage within the normal range under varying active power generated by the PV systems, and simulation results verify that the total reactive power output of the PV inverters can be effectively reduced.
关键词： distribution network,residential photovoltaic system,grid-connected inverters,voltage Sensitivity,Decentralized control
更新于2025-09-19 17:13:59
-
Air-Filled Substrate Integrated Waveguide Leaky-Wave Antenna with Wideband and Fixed-Beam Characteristics
摘要： An output line-to-line voltage model-based fault diagnostic technique is presented in this paper. From the theoretical analysis of the output voltage under normal and faulty conditions, a preprocessing method is developed to extract fault features from diagnosis eigenvalue. A voltage envelope line is generated by the proposed voltage envelope function. By comparing the preprocessed diagnosis eigenvalue and the voltage envelope, single-switch open-circuit faults can be located precisely. Because the proposed method does not rely on the accurate amplitude of the output line-to-line voltage, the influence of the load changing is minimized and simple hardware is adopted, which has advantages of low cost, high reliability, and short diagnosis time. Moreover, as long as the inverter output voltages have the feature of periodic nonpositive and nonnegative, this method is valid no matter what control strategy is adopted by the inverter and no control signal is required for the diagnosis process. The prototype system is tested to validate the adaptability of the proposed method under different conditions, such as the diverse loads, various control strategies, and fault-occurrence time.
关键词： Fault diagnosis,fault location,open-circuit fault,inverters
更新于2025-09-19 17:13:59
-
A Non-Isolated Buck-Boost DC-DC Converter with Continuous Input Current for Photovoltaic Applications
摘要： High-power grinding mills are used in the cement and mining industries to crush clinker or copper ore and grind these materials to fine powder. The multi-megawatt speed-controlled mill drives operate at a very low angular speed. Synchronous motors with a high number of pole pairs are used as the prime movers. They are traditionally fed by load-commutated thyristorized cycloconverters. These are prone to failure modes that can lead to excessive torque pulsations and high overcurrents. The huge stator, which was built as a separate ring-shaped structure around the tubular mill, may then get mechanically displaced, and the operation of the plant is interrupted. A novel and reliable direct drive uses a voltage source inverter that operates at the unity power factor for increased efficiency. Synchronous optimal pulsewidth modulation ensures a low harmonic current distortion and reduced switching losses at a very low switching frequency. The optimization of the pulse patterns takes the anisotropic magnetic properties of a separately excited synchronous motor into account. The implementation in a 23-MW semiautonomous grinding mill installed in a Zambian copper mine is intended.
关键词： Alternators,pulse width modulation inverters,gradient methods,ball milling,software algorithms,variable speed drives,Fourier transform
更新于2025-09-19 17:13:59