- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Comparative Evaluation of Lifetime of Three-Level Inverters in Grid-Connected Photovoltaic Systems
摘要： The cost of the PV energy reduction is still required to increase the penetration level of PV systems in the energy market. The reliability of PV inverters is one of the important aspects to be enhanced in order to reduce the cost of PV energy, since it is closely related to the maintenance cost and the annual energy production. In this paper, the lifetime of NPC and T-type inverters, which are three-level inverter topologies that are widely used for PV systems, are comparatively evaluated with a 30 kW grid-connected PV system. It is performed by focusing on power devices since the power electronic components of both converters are the same except for the power devices. Therefore, this result can represent the comparison of the reliability performance of the NPC and T-type inverters. The power loss and temperature distributions of power devices are analyzed and their e?ciencies are compared at di?erent power levels with di?erent switching frequencies. The lifetimes of the reliability-critical power devices in the NPC and T-type inverters are estimated, respectively with a one-year mission pro?le of the PV system, and the results are compared.
关键词： three-level inverter,IGBT module,PV inverter,reliability,power device,lifetime
更新于2025-09-19 17:13:59
-
P-Q capability chart analysis of multi-inverter photovoltaic power plant connected to medium voltage grid
摘要： This paper presents the proposal of the methodology for the development of realistic P-Q capability chart at point of common coupling of photovoltaic power plant, comprised of multiple inverter units and connected to medium voltage grid. Theoretical equations for the contribution to the total active and reactive power of the plant are derived for all plant components: inverters, low voltage cables, transformers, medium voltage cables and auxiliary consumption. It is concluded that equations for total active and reactive power are dependable on only two changing variables: voltage and momentary generation power of inverters. Equations for maximum and minimum values for total active and reactive power are further derived when known maximum and minimum values of changing variables are entered to equations, and these are presented on graph diagram as curves. Area in P-Q diagram within such calculated border curves is area of possible power plant operation points at the point of common coupling. Such representation model of this type of plant has not been proposed before. The proposed methodology has been applied to the case study plant and its operation P-Q diagram is constructed Measurements conducted on this case study plant are compared with calculated values for necessary corrections to the model.
关键词： Multi-inverter,Medium voltage grid,P-Q capability chart,Photovoltaic power plant,Reactive power
更新于2025-09-19 17:13:59
-
[IEEE 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Waikoloa Village, HI (2018.6.10-2018.6.15)] 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - A Fast Quasi-Static Time Series Simulation Method for PV Smart Inverters with VAR Control using Linear Sensitivity Model
摘要： Fast deployment of renewable energy resources in distribution networks, especially solar photovoltaic (PV) systems, have motivated the need for inverter-based voltage regulation. Integration studies are often necessary to fully understand the potential impacts of PV inverter settings on the various elements of the distribution system, including voltage regulators and capacitor banks. A year long quasi-static time series (QSTS) at second-level granularity provides a comprehensive assessment of these impacts, however the computational burden associated with running QSTS limits its applicability. This paper proposes a fast QSTS simulation technique capable of modeling the smart inverter dynamic VAR control functionality and accurately estimating the states of controllable elements including voltage regulators and capacitor banks at each time step. Consequently, the complex interactions between various legacy voltage regulation devices is also captured. The efficacy of the proposed algorithm is demonstrated on the IEEE 13-bus test case with a 98% reduction in computation time.
关键词： multiple linear regression,smart inverter,voltage control,Quasi-static time series,PV impact studies
更新于2025-09-19 17:13:59
-
[IEEE 2019 International Conference on Electrical and Computing Technologies and Applications (ICECTA) - Ras Al Khaimah, United Arab Emirates (2019.11.19-2019.11.21)] 2019 International Conference on Electrical and Computing Technologies and Applications (ICECTA) - Controlled Reactive Power Supplied to Grid by Photovoltaic Connected
摘要： in the upcoming years, photovoltaic systems are predicted to be one of the main sources of electricity, the amount of installed photovoltaic power has rapidly increased. But using photovoltaic systems connected to grid may have drawback effect on the grid parameters. with using more and more photovoltaic panel energy its necessary to investigate them into the power systems, because small residential loads using photovoltaic at maximum power as the main source of the power and the utility use as a backup source interfaced with inverter and this change the characteristics of power flow shape and effect the parameter of the grid, this paper will focus on increase reactive power problem and discuss the ability of solution by control of reactive power and active power of photovoltaic inverter output to improve the efficiency of the grid.
关键词： Inverter control,Connected to Grid,Photovoltaic,Reactive power
更新于2025-09-19 17:13:59
-
Direct Usage of Photovoltaic Solar Panels to Supply a Freezer Motor with Variable DC Input Voltage
摘要： In this paper, a single-phase photovoltaic (PV) inverter fed by a boost converter to supply a freezer motor with variable DC input is investigated. The proposed circuit has two stages. Firstly, the DC output of the PV panel that varies between 150 and 300 V will be applied to the boost converter. The boost converter will boost the input voltage to a fixed 300 V DC. Next, this voltage is supplied to the single-phase full bridge inverter to obtain 230 V AC. In the end, The output of the inverter will feed a freezer motor. The PV panels can be stand-alone or grid-connected. The grid-connected PV is divided into two categories, such as with a transformer and without a transformer, a transformer type has galvanic isolation resulting in increasing the security and also provides no further DC current toward the grid, but it is expensive, heavy and bulky. The transformerless type holds high efficiency and it is cheaper, but it suffers from leakage current between PV and the grid. This paper proposes a stand-alone direct use of PV to supply a freezer; therefore, no grid connection will result in no leakage current between the PV and Grid. The proposed circuit has some features such as no filtering circuit at the output of the inverter, no battery in the system, DC-link instead of AC link that reduces no-loads, having a higher efficiency, and holding enough energy in the DC-link capacitor to get the motor started. The circuit uses no transformers, thus, it is cheaper and has a smaller size. In addition, the system does not require a complex pulse width modulation (PWM) technique, because the motor can operate with a pulsed waveform. The control strategy uses the PWM signal with the desired timing. With this type of square wave, the harmonics (5th and 7th) of the voltage are reduced. The experimental and simulation results are presented to verify the feasibility of the proposed strategy.
关键词： photovoltaic,boost converter,pulse width modulation,single-phase inverter
更新于2025-09-19 17:13:59
-
Optimized reactive power support strategy for photovoltaic inverter to intensify the dynamic voltage stability of islanded microgrid
摘要： This study presents an innovative and optimized reactive power support (ORPS) strategy for photovoltaic (PV) inverters to improve the dynamic voltage stability (DVS) of islanded microgrid (MG) with induction motor (IM) load. On the occurrence of the fault, voltage instability (VI) happens due to the low-inertia IM load and poor ride through capability of PV inverters of MG. Supplement of optimal RPS promptly, without exceeding the rated current value of the inverter, is aimed at the proposed control, to maintain DVS during severe voltage downfall as a result of a fault. Once the profiled voltage value is restored and the necessity of RPS is fulfilled, the PV inverter returns to its prefault power production combination. The detailed model of an inverter-based islanded MG with IM load is built to examine the DVS, and the theoretical analysis and technical discussion are conducted. A comparison between the conventional and proposed strategies is carried out. From the demonstrated results, employing the proposed ORPS control can provide RPS effectively and helps to improve the DVS. This proposed strategy can also provide an equivalent service as an expensive 610-kVA dynamic volt-ampere reactive support device (ie, D-STATCOM) in the studied MG.
关键词： PV inverter,dynamic voltage stability,reactive power support strategy,islanded MG
更新于2025-09-19 17:13:59
-
[IEEE 2019 Eleventh International Conference on Ubiquitous and Future Networks (ICUFN) - Zagreb, Croatia (2019.7.2-2019.7.5)] 2019 Eleventh International Conference on Ubiquitous and Future Networks (ICUFN) - Implement of 100-Gbps optical transceiver firmware for optical communication systems
摘要： This paper proposes a new fast technique, in which the slope of a photovoltaic (PV) inverter current is utilized to predict if the current is expected to exceed its rated value due to any grid faults. Two applications of this technique are demonstrated. In jurisdictions where grid codes require distributed generators (DGs) to disconnect after a fault occurrence, such as in Ontario, Canada, this technique is utilized to rapidly disconnect the PV solar system even before the inverter short circuit current actually exceeds the rated current of the inverter, thereby obviating the problem of any adverse short circuit current contribution into the grid. However, in regions where grid codes require DGs to stay connected and provide grid support, such as low-voltage ride through, this technique can be used to rapidly and autonomously transform the PV solar farm into a dynamic reactive power compensator STATCOM (termed PV-STATCOM) for providing voltage support function. In this paper, the PV-STATCOM is used to stabilize a critical induction motor load in the vicinity of the solar farm, which would have otherwise become unstable due to the grid fault. PSCAD-based simulation studies are performed on a realistic distribution network to demonstrate the effectiveness of this technique.
关键词： STATCOM,Distributed generator (DG),inverter,flexible AC transmission system (FACTS),protection,short circuit current,PV-STATCOM,photovoltaic (PV) systems
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - IEEE 1547-2018 Based Interoperable PV Inverter with Advanced Grid-Support Functions
摘要： Grid integration of photovoltaic (PV) inverters has been increasing in the past decade. As a result of the uncertainties introduced with high penetrations of PV, better monitoring and control of the PV inverters becomes crucial for improving overall system stability. This paper focuses on the communications capability of the inverter controller and on enabling interoperability. Multiple standards are available to enable interoperability in PV inverters. In this paper, an interoperable controller, enabled by Distributed Network Protocol 3 (DNP3) communications protocols, is developed for a grid-connected, three-phase PV inverter. The DNP3 server for the PV inverter is programmed on the real-time layer of the field-programmable gate array (FPGA)-based inverter controller. Set points for advanced inverter control functions, such as volt/VAr curves, ride-through curves, are sent from a DNP3 client, a simulated distribution management system application, to the PV inverter through DNP3. This communications capability of the inverter controller is validated using a controller-hardware-in-the-loop experimental setup. The code developed to achieve the interoperability is available in the public domain through open-source software licensing. This interoperability will enable smoother grid integration of smart PV inverters with advanced grid-support functions as well as allow better monitoring and control of PV inverters for grid stability.
关键词： Distributed Network Protocol,DNP3,PV inverter,advanced grid-support functions,interoperability
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 2nd International Conference on Knowledge Innovation and Invention (ICKII) - Seoul, Korea (South) (2019.7.12-2019.7.15)] 2019 IEEE 2nd International Conference on Knowledge Innovation and Invention (ICKII) - PV System Power Model Application in Smart Cities
摘要： The photovoltaic (PV) system energy generation is closely related to climate conditions, installation site, and system design. In this paper, a simple energy generation model is proposed and established by means of module temperature and solar irradiation, module temperature coefficient, module rated power, number of modules, and three correction coefficients including temperature derating coefficient, inverter conversion loss coefficient, and other loss coefficients. The experiment results show that the estimation model proposed in this paper has high accuracy using the Mean Absolute Percentage Error (MAPE) model as the evaluation index, the estimation model MAPE is 6.75%, while the PV SYST software simulation has MAPE of 11.90%. According to international MAPE evaluation standards, the method proposed in this paper has higher accuracy level than PV SYST software. This model can be used for the estimation of energy generation when installing solar PV systems, and can be used for the reasonable assessment of PV system long-term power generation, to predict system power generation anomalies, and reduce system abnormalities caused by downtime losses, and increase investment efficiency.
关键词： PV system,module,power model,inverter
更新于2025-09-19 17:13:59
-
[IEEE 2019 Chinese Automation Congress (CAC) - Hangzhou, China (2019.11.22-2019.11.24)] 2019 Chinese Automation Congress (CAC) - Research on reactive compensation and grid-connected photovoltaic control strategy of a nRYHO type energy storage Quasi-z-source inverter
摘要： A combined control strategy of photovoltaic grid-connection, reactive power compensation and energy storage was proposed for a novel energy storage quasi-z source inverter. According to the different state of the battery, the system applies different control schemes. Based on the control strategy of the battery under normal conditions, this paper analyzes and discusses the unit power factor grid-connected, while ensuring the maximum utilization of photovoltaic cell energy efficiency and enhancing the stability of grid-connected power, and compensates the load with reactive power. Finally, simulation and experiment verify the effectiveness and correctness of the proposed strategy.
关键词： Unit power factor grid-connected,Quasi-z-source inverter,Reactive power compensation,Energy storage
更新于2025-09-19 17:13:59