- 标题
- 摘要
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- 实验方案
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[IEEE 2018 IEEE Power & Energy Society General Meeting (PESGM) - Portland, OR, USA (2018.8.5-2018.8.10)] 2018 IEEE Power & Energy Society General Meeting (PESGM) - Comparative Study of Active Power Curtailment Methods of PVs for Preventing Overvoltage on Distribution Feeders
摘要： Overvoltage is one of the major issues on distribution grids with high penetration of photovoltaic (PV) generation. Overvoltage could be prevented through the control of active/reactive power of PVs. However, given the high R/X ratio of low voltage feeders, voltage control by using reactive power would not be as effective as using active power. Therefore, active power curtailment (APC) of PVs, though not desirable, becomes necessary at times to prevent the overvoltage issues. Existing literature is rich in centralized and droop-based methods for APC and/or reactive power control of PVs to prevent overvoltage issues. In this context, this paper revisits the most popular existing methods, and evaluates the performance of droop-based and centralized methods using a typical North American 240 V low voltage feeder with 24 residential homes. In this work, our key findings are: a) droop-based methods provided conservative solutions or did not eliminate the overvoltages completely, b) power flow sensitivity based droop approach led to 13% more curtailment than the centralized approaches, c) centralized approach had 40% less energy curtailed compared with standard droop while no overvoltages were observed, and d) operating PVs at non-unity power factor in centralized approach led to 5% less energy curtailment.
关键词： Inverter,Overvoltage,Photovoltaic,Power Curtailment,Voltage Control,Distribution Grid
更新于2025-09-23 15:23:52
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Impact of Grid Voltage Feed-Forward Filters on Coupling between DC-Link Voltage and AC Voltage Controllers in Smart PV Solar Systems
摘要： This paper presents a novel study of impact of filters of grid voltage feed-forward signals on the coupling between dc-link voltage and ac voltage controllers in smart photovoltaic (PV) solar systems which are used for voltage control in distribution systems. A comprehensive linearized state space model of a PV system including the dynamics of grid voltage feed-forward filters, dc-link voltage and ac voltage controllers is developed for the first time. This model is validated by electromagnetic transients software PSCAD/EMTDC. This model is used to identify the coupling between dc-link voltage and ac voltage controllers by eigenvalue and participation factor analyses. The impact of time constant of feed-forward filters on this coupling is studied by eigenvalue sensitivity analysis for PV systems with Proportional and Proportional Integral type ac voltage controllers. The range of time constants over which the filters interact with controllers and create instability for systems with different strengths and X/R ratios is identified. Insights are provided on the choice of time constants of grid voltage feed-forward filters for stable system design. The developed state-space model can also be used for impact studies of various other parameters e.g. system strength, X/R ratios, types and gains of controllers, on system stability.
关键词： AC Voltage Control,Smart Inverter,Photovoltaic (PV) System,Reactive Power Control,Control Interaction
更新于2025-09-23 15:22:29
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Model Predictive Voltage Control Based on Finite Control Set with Computation Time Delay Compensation for PV Systems
摘要： For the conservativeness and computational delay of the traditional finite control set model predictive control (FCS-MPC), a multi-step model predictive voltage control method based on finite control set (FCS-MMPVC) with delay compensation method is proposed in this paper, and the proposed method is validated on a three-level three-phase voltage source PV inverter. In each control cycle, the twenty-seven voltage vectors for inverters are evaluated on line based on predictive model to obtain the optimal and suboptimal switching state. The selected switching state is optimal in two control cycle with the proposed method. Considering that the time spent in the actual sampling and calculation process cannot be ignored, the delay compensation is added in FCS-MMPVC algorithm. The simulation and experimental results show that the proposed method has good stability and reliability. Compared with the traditional FCS-MPC algorithm, the proposed method can reduce the difference significantly between the output voltage and the reference under the unbalanced and non-linear load, and the output voltage quality of the inverter is improved.
关键词： Delay compensation,Multi-step model predictive voltage control,PV inverter,Finite control set
更新于2025-09-23 15:21:21
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DC-Bus Dual-Level Control Strategy for PV Power System with Dual-Mode Operation
摘要： An autonomous dc-bus dual-level control (DDLC) strategy is proposed for the two-stage three-phase photovoltaic (PV) power system. During the grid-fault situation, the second-stage inverter may lose the ability to regulate the dc-bus voltage and the first-stage boost converter has to change its mode from maximum power point tracking (MPPT) mode to dc-bus voltage control (DCVC) mode. However, the communication between the two-stage circuits must be established. The circuit complexity and cost will increase while the system’s scalability and flexibility will be reduced. With the proposed DDLC strategy, the dc-bus voltage is controlled into different levels for different operation modes, without the need of communication mechanism. No extra sensors or circuits are required. Two important design parameters for the proposed DDLC are derived thoroughly. The computer simulations and hardware experimental results of a 4 kVA prototype circuit are presented to validate the performance of the proposed DDLC strategy.
关键词： Optimal AC Line Current Regulation,Maximum Power Point Tracking (MPPT),PV Power System,DC-Bus Voltage Control (DCVC)
更新于2025-09-23 15:21:21
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[IEEE 2018 IEEE PES/IAS PowerAfrica - Cape Town, South Africa (2018.6.28-2018.6.29)] 2018 IEEE PES/IAS PowerAfrica - A Review of Grid Tied PV Generation on LV Distribution Networks
摘要： Renewable generation, at the customer side of the meter, continue to gain interest worldwide. Distribution network (DN) performance analysis, under distributed photovoltaic generation (DPVG), is paramount important to ensure DN security and reliability. This paper presents a broad review of issues, with an emphasis on grid voltage, associated with DSPVG, and proposed solutions. There has not been a comprehensive literature review of DSPVG, particularly in South Africa (SA). There is a need to quantify impacts and expectations of DSPVG connection on three phase radial low voltage (LV) DNs. In this paper, circuit diagrams and mathematical expressions for voltage rise and drop analyses, are detailed, with a comprehensive range of proposed and commercially available mitigation solutions. These include; active power curtailment (APC), reactive power control (RPC) and droop-based voltage control. APC is more ef?cient and effective for LV DNs. Sophisticated strategies combining different standalone control methods, were proposed in literature, for increase of DSPVG penetration, both locally, in residential home, and globally.
关键词： Distribution network,low voltage,voltage control,photovoltaic
更新于2025-09-23 15:21:01
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[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
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[IEEE 2019 20th International Conference on Intelligent System Application to Power Systems (ISAP) - New Delhi, India (2019.12.10-2019.12.14)] 2019 20th International Conference on Intelligent System Application to Power Systems (ISAP) - Voltage Control Using Smart Transformer for Increasing Photovoltaic Penetration in a Distribution Grid
摘要： Uncertainty and variation of power generation through photovoltaic (PV) sources are major challenges for their integration with the distribution grid. Voltage rise and voltage drop issues limit the increase in PV penetration and loading level, respectively. It is important to maintain voltage levels within specified limits of grid code for providing long life, more efficiency, and good performance of consumer equipment while ensuring that the PV power generation is not curtailed. In this paper, a voltage control method for the smart transformer (ST) is proposed to improve voltage profile in the distribution network. Voltage control capability for ST is added through the method of switching among three setpoints based on the voltage. The proposed method is compared with the conventional method of switching between two setpoints based on current. The proposed method provides better voltage profile in the distribution network as compared to conventional method. Performance indicators are developed to understand the impact of voltage control methods on the system voltage profile. Proposed voltage control method is tested on a CIGRE low voltage residential distribution network.
关键词： voltage control,smart transformer,Renewable energy sources
更新于2025-09-23 15:21:01
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[IEEE 2018 International Power Electronics Conference (IPEC-Niigata 2018 –ECCE Asia) - Niigata, Japan (2018.5.20-2018.5.24)] 2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia) - Adaptive voltage control scheme for DAB based modular cascaded SST in PV application
摘要： Solid state transformer (SST) is able to interface PV panels and distributed grid, which could serve as a new structure for future PV plants. However, the wide operating voltage range of PV system reduces the efficiency of DAB based modular cascaded SST system. Thus, this paper analyzes the impact of DAB voltage deviation between input and output side under frequency component analysis. Besides adjusting primary and secondary side duty cycles, which is widely used in previous literature, this paper utilizes DAB output voltage as an extra control freedom in SST. Then, an adaptive voltage control (AVC) scheme is proposed, which changes DAB output voltage in accordance with input voltage. This paper presents the detailed implementation of AVC and thoroughly compares SST cell efficiency with previous modulation method. Finally, the proposed method is verified in 10kV/1MW SST system.
关键词： SST,DAB,efficiency,Adaptive voltage control
更新于2025-09-23 15:21:01
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A novel control strategy to mitigate slow and fast fluctuations of the voltage profile at common coupling Point of rooftop solar PV unit with an integrated hybrid energy storage system
摘要： A high penetration of rooftop solar photo-voltaic (PV) units can cause both slow and fast voltage fluctuations when connected to the low voltage (LV) distribution feeder due to the random variations in the solar PV power output versus load demand. These unacceptable fluctuations can be alleviated by using energy storage systems integrated with the solar PV units. In this paper, a novel heuristic control strategy is proposed to alleviate both the slow and fast voltage fluctuations in the connected LV distribution feeder; using a hybrid energy storage system. In the proposed method; the integrated battery storage will be dynamically charged to mitigate the voltage rise during mid-day, and discharged during the evening peak hours, and the integrated super capacitor storage will be simultaneously charged or discharged to control the fast fluctuations in the PV inverter to be within a specified magnitude. An energy sharing method between the battery storage and the super capacitor storage is proposed to provide undisrupted control for the fast fluctuations during passing cloud. The proposed control strategies have been verified on a distribution feeder system and the results have been reported.
关键词： Slow fluctuations,Rooftop solar PV,Battery storage,Voltage control,Fast fluctuations,Hybrid energy storage system,Super capacitor storage
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Test-Based Modeling of Photovoltaic Inverter Impact on Distribution Systems
摘要： AC voltage regulation is required in both the domestic and industrial sectors to avoid undesired effects from random voltage variations of the power supply. The paper introduces an ac voltage stabilizer/converter (ACVS) that is based on a controllable autotransformer technology. The proposed ACVS offers a specified strategy of voltage regulation, less harmonics, and low cost. The paper explains the operating principle of the ACVS and derives its nonlinear mathematical model. To ensure the desired performance of the ACVS while it is subject to uncertain input voltage and load variations, an optimal control strategy is designed. It is achieved via transforming the ACVS model extending with fictive axis emulation into a rotating reference frame and the linearization of the model via specific orientation of the reference frame and introducing a linear control action. Operation of the ACVS is simulated under different disturbances due to load and grid voltage changes, and compared to voltage stabilization with application of I and PI controllers. Experimental results are presented to demonstrate the voltage regulation technology.
关键词： AC–AC power conversion,electric variables control,linear-quadratic control,power quality,voltage control
更新于2025-09-23 15:19:57