This paper presents an analysis of the effect of parasitic resistances on the performance of DC-DC Single Ended Pri- mary Inductor Converter (SEPIC) in photovoltaic maximum power point tracking (MPPT) applications. Th...This paper presents an analysis of the effect of parasitic resistances on the performance of DC-DC Single Ended Pri- mary Inductor Converter (SEPIC) in photovoltaic maximum power point tracking (MPPT) applications. The energy storage elements incorporated in the SEPIC converter possess parasitic resistances. Although ideal components significantly simplifies model development, but neglecting the parasitic effects in models may sometimes lead to failure in predicting first scale stability and actual performance. Therefore, the effects of parasitics have been taken into consideration for improving the model accuracy, stability, robustness and dynamic performance analysis of the converter. Detail mathematical model of SEPIC converter including inductive parasitic has been developed. The performance of the converter in tracking MPP at different irradiance levels has been analyzed for variation in parasitic resistance. The converter efficiency has been found above 83% for insolation level of 600 W/m2 when the parasitic resistance in the energy storage element has been ignored. However, as the parasitic resistance of both of the inductor has increased to 1 ohm, a fraction of the power managed by the converter has dissipated;as a result the efficiency of the converter has reduced to 78% for the same insolation profile. Although the increasing value of the parasitic has assisted the converter to converge quickly to reach the maximum power point. Furthermore it has also been observed that the peak to peak load current ripple is reduced. The obtained simulation results have validated the competent of the MPPT converter model.展开更多
Solar power is mostly influenced by solar irradiation,weather conditions,solar array mismatches and partial shading conditions.Therefore,before installing solar arrays,it is necessary to simulate and determine the pos...Solar power is mostly influenced by solar irradiation,weather conditions,solar array mismatches and partial shading conditions.Therefore,before installing solar arrays,it is necessary to simulate and determine the possible power generated.Maximum power point tracking is needed in order to make sure that,at any time,the maximum power will be extracted from the photovoltaic system.However,maximum power point tracking is not a suitable solution for mismatches and partial shading conditions.To overcome the drawbacks of maximum power point tracking due to mismatches and shadows,distributed maximum power point tracking is util-ized in this paper.The solar farm can be distributed in different ways,including one DC-DC converter per group of modules or per module.In this paper,distributed maximum power point tracking per module is implemented,which has the highest efficiency.This technology is applied to electric vehicles(EVs)that can be charged with a Level 3 charging station in<1 hour.However,the problem is that charging an EV in<1 hour puts a lot of stress on the power grid,and there is not always enough peak power reserve in the existing power grid to charge EVs at that rate.Therefore,a Level 3(fast DC)EV charging station using a solar farm by implementing distributed maximum power point tracking is utilized to address this issue.Finally,the simulation result is reported using MATLAB®,LTSPICE and the System Advisor Model.Simulation results show that the proposed 1-MW solar system will provide 5 MWh of power each day,which is enough to fully charge~120 EVs each day.Additionally,the use of the proposed photovoltaic system benefits the environment by removing a huge amount of greenhouse gases and hazardous pollutants.For example,instead of supplying EVs with power from coal-fired power plants,1989 pounds of CO_(2) will be eliminated from the air per hour.展开更多
This paper proposes an effective Maximum Power Point Tracking (MPPT) controller being incorporated into a solar Photovoltaic system supplying a Brushless DC (BLDC) motor drive as the load. The MPPT controller makes us...This paper proposes an effective Maximum Power Point Tracking (MPPT) controller being incorporated into a solar Photovoltaic system supplying a Brushless DC (BLDC) motor drive as the load. The MPPT controller makes use of a Genetic Assisted Radial Basis Function Neural Network based technique that includes a high step up Interleaved DC-DC converter. The BLDC motor combines a controller with a Proportional Integral (PI) speed control loop. MATLAB/Simulink has been used to construct the dynamic model and simulate the system. The solar Photovoltaic system uses Genetic Assisted-Radial Basis Function-Neural Network (GA-RBF-NN) where the output signal governs the DC-DC boost converters to accomplish the MPPT. This proposed GA-RBF-NN based MPPT controller produces an average power increase of 26.37% and faster response time.展开更多
温差发电(thermoelectric generation,TEG)系统作为一种清洁可再生的新能源发电装置,通过最大功率点跟踪(maximum power point tracking,MPPT)控制器连续跟踪输出功率的最大值极其重要。针对TEG系统侧存在功率振荡、功率跟踪速度慢、跟...温差发电(thermoelectric generation,TEG)系统作为一种清洁可再生的新能源发电装置,通过最大功率点跟踪(maximum power point tracking,MPPT)控制器连续跟踪输出功率的最大值极其重要。针对TEG系统侧存在功率振荡、功率跟踪速度慢、跟踪精度差等问题,文中在硬件电路上对比了不同DC-DC变换器的特点,选定能减缓功率振荡的二次型Boost电路作为MPPT的主电路。同时,在MPPT的算法策略上,文中提出一种基于优化初值的增量电导法(OI-INC),首先,通过分析TEG的电流—电压输出特性和二次型Boost电路的等效模型,计算并输出近似的最优占空比,快速跟踪到最大功率点附近,优化增量电导法的初值;之后,采用较小的扰动步长实现高质量MPPT。在含有启动、恒温、均匀升温、快速升温4种工况的复杂时变环境下,与扰动观察法、增量电导法相比,仿真结果表明:文中所提出的MPPT策略不仅能压缩跟踪时间、提高跟踪精度,还能减轻功率振荡问题。展开更多
针对两级光伏系统在电网电压穿越时难以对直流系统电压进行快速稳定调控的问题,提出一种功率-电压混合控制策略。并网电压较为稳定时,并网逆变器进行直流电压调控,升压电路工作在最大功率跟踪(Maximum power point tracking,MPPT)模式;...针对两级光伏系统在电网电压穿越时难以对直流系统电压进行快速稳定调控的问题,提出一种功率-电压混合控制策略。并网电压较为稳定时,并网逆变器进行直流电压调控,升压电路工作在最大功率跟踪(Maximum power point tracking,MPPT)模式;并网电压穿越时,逆变器保持对直流电压的调控能力,升压电路由MPPT控制切换到电压控制,实现对直流电压的快速、稳定调控,降低直流电压波动量,提高直流系统的电压稳定性。为了证实提出的功率-电压混合控制策略在电压穿越时对直流系统的稳定调控能力,基于RT-LAB半实物测试平台,进行了并网光伏系统电压穿越时的动态试验。试验结果表明,相比于传统控制策略,在电压穿越时,改进的功率-电压混合控制策略能够将直流系统的电压波动量从78V减小到7.7V,将电压波动率从19.5%降低到1.9%,提高了直流系统的电压稳定性。展开更多
针对直流配电系统消纳新能源发电模式下缺乏直流型变换器的现状,基于交错并联Boost拓扑结构,结合扰动观察法最大功率点跟踪(Maximum Power Point Tracking,MPPT)控制策略,采用电压电流双闭环的控制模式,开发了直流型光伏DC/DC变换器。...针对直流配电系统消纳新能源发电模式下缺乏直流型变换器的现状,基于交错并联Boost拓扑结构,结合扰动观察法最大功率点跟踪(Maximum Power Point Tracking,MPPT)控制策略,采用电压电流双闭环的控制模式,开发了直流型光伏DC/DC变换器。对直流型光伏DC/DC变换器的调试表明,该变换器可实现光伏发电的高效化最大功率点跟踪,输出稳定的直流电压,长时间带载实验表明该变换器具有稳定且高效的运行特性。展开更多
文摘This paper presents an analysis of the effect of parasitic resistances on the performance of DC-DC Single Ended Pri- mary Inductor Converter (SEPIC) in photovoltaic maximum power point tracking (MPPT) applications. The energy storage elements incorporated in the SEPIC converter possess parasitic resistances. Although ideal components significantly simplifies model development, but neglecting the parasitic effects in models may sometimes lead to failure in predicting first scale stability and actual performance. Therefore, the effects of parasitics have been taken into consideration for improving the model accuracy, stability, robustness and dynamic performance analysis of the converter. Detail mathematical model of SEPIC converter including inductive parasitic has been developed. The performance of the converter in tracking MPP at different irradiance levels has been analyzed for variation in parasitic resistance. The converter efficiency has been found above 83% for insolation level of 600 W/m2 when the parasitic resistance in the energy storage element has been ignored. However, as the parasitic resistance of both of the inductor has increased to 1 ohm, a fraction of the power managed by the converter has dissipated;as a result the efficiency of the converter has reduced to 78% for the same insolation profile. Although the increasing value of the parasitic has assisted the converter to converge quickly to reach the maximum power point. Furthermore it has also been observed that the peak to peak load current ripple is reduced. The obtained simulation results have validated the competent of the MPPT converter model.
基金support of the National Science Foundation(NSF)under Award Number:2115427 is gratefully acknowledged.SRS RN:Sustainable Transportation Electrification for an Equitable and Resilient Society(STEERS).
文摘Solar power is mostly influenced by solar irradiation,weather conditions,solar array mismatches and partial shading conditions.Therefore,before installing solar arrays,it is necessary to simulate and determine the possible power generated.Maximum power point tracking is needed in order to make sure that,at any time,the maximum power will be extracted from the photovoltaic system.However,maximum power point tracking is not a suitable solution for mismatches and partial shading conditions.To overcome the drawbacks of maximum power point tracking due to mismatches and shadows,distributed maximum power point tracking is util-ized in this paper.The solar farm can be distributed in different ways,including one DC-DC converter per group of modules or per module.In this paper,distributed maximum power point tracking per module is implemented,which has the highest efficiency.This technology is applied to electric vehicles(EVs)that can be charged with a Level 3 charging station in<1 hour.However,the problem is that charging an EV in<1 hour puts a lot of stress on the power grid,and there is not always enough peak power reserve in the existing power grid to charge EVs at that rate.Therefore,a Level 3(fast DC)EV charging station using a solar farm by implementing distributed maximum power point tracking is utilized to address this issue.Finally,the simulation result is reported using MATLAB®,LTSPICE and the System Advisor Model.Simulation results show that the proposed 1-MW solar system will provide 5 MWh of power each day,which is enough to fully charge~120 EVs each day.Additionally,the use of the proposed photovoltaic system benefits the environment by removing a huge amount of greenhouse gases and hazardous pollutants.For example,instead of supplying EVs with power from coal-fired power plants,1989 pounds of CO_(2) will be eliminated from the air per hour.
文摘This paper proposes an effective Maximum Power Point Tracking (MPPT) controller being incorporated into a solar Photovoltaic system supplying a Brushless DC (BLDC) motor drive as the load. The MPPT controller makes use of a Genetic Assisted Radial Basis Function Neural Network based technique that includes a high step up Interleaved DC-DC converter. The BLDC motor combines a controller with a Proportional Integral (PI) speed control loop. MATLAB/Simulink has been used to construct the dynamic model and simulate the system. The solar Photovoltaic system uses Genetic Assisted-Radial Basis Function-Neural Network (GA-RBF-NN) where the output signal governs the DC-DC boost converters to accomplish the MPPT. This proposed GA-RBF-NN based MPPT controller produces an average power increase of 26.37% and faster response time.
文摘温差发电(thermoelectric generation,TEG)系统作为一种清洁可再生的新能源发电装置,通过最大功率点跟踪(maximum power point tracking,MPPT)控制器连续跟踪输出功率的最大值极其重要。针对TEG系统侧存在功率振荡、功率跟踪速度慢、跟踪精度差等问题,文中在硬件电路上对比了不同DC-DC变换器的特点,选定能减缓功率振荡的二次型Boost电路作为MPPT的主电路。同时,在MPPT的算法策略上,文中提出一种基于优化初值的增量电导法(OI-INC),首先,通过分析TEG的电流—电压输出特性和二次型Boost电路的等效模型,计算并输出近似的最优占空比,快速跟踪到最大功率点附近,优化增量电导法的初值;之后,采用较小的扰动步长实现高质量MPPT。在含有启动、恒温、均匀升温、快速升温4种工况的复杂时变环境下,与扰动观察法、增量电导法相比,仿真结果表明:文中所提出的MPPT策略不仅能压缩跟踪时间、提高跟踪精度,还能减轻功率振荡问题。
文摘针对两级光伏系统在电网电压穿越时难以对直流系统电压进行快速稳定调控的问题,提出一种功率-电压混合控制策略。并网电压较为稳定时,并网逆变器进行直流电压调控,升压电路工作在最大功率跟踪(Maximum power point tracking,MPPT)模式;并网电压穿越时,逆变器保持对直流电压的调控能力,升压电路由MPPT控制切换到电压控制,实现对直流电压的快速、稳定调控,降低直流电压波动量,提高直流系统的电压稳定性。为了证实提出的功率-电压混合控制策略在电压穿越时对直流系统的稳定调控能力,基于RT-LAB半实物测试平台,进行了并网光伏系统电压穿越时的动态试验。试验结果表明,相比于传统控制策略,在电压穿越时,改进的功率-电压混合控制策略能够将直流系统的电压波动量从78V减小到7.7V,将电压波动率从19.5%降低到1.9%,提高了直流系统的电压稳定性。
文摘针对直流配电系统消纳新能源发电模式下缺乏直流型变换器的现状,基于交错并联Boost拓扑结构,结合扰动观察法最大功率点跟踪(Maximum Power Point Tracking,MPPT)控制策略,采用电压电流双闭环的控制模式,开发了直流型光伏DC/DC变换器。对直流型光伏DC/DC变换器的调试表明,该变换器可实现光伏发电的高效化最大功率点跟踪,输出稳定的直流电压,长时间带载实验表明该变换器具有稳定且高效的运行特性。
