Because of rich solar resource and low land cost, a lot of large-scale ground-based grid-connected PV systems have been built in Northwest China. In this paper, some shading phenomena on a grid-connected PV system inN...Because of rich solar resource and low land cost, a lot of large-scale ground-based grid-connected PV systems have been built in Northwest China. In this paper, some shading phenomena on a grid-connected PV system inNorthwest Chinaare classified and analyzed. Through the I-V curve test of PV modules, it can be seen that dust influence system performance of the grid-connected PV system. And the experimental results have shown that shading could affect the electrical properties of PV modules. Meanwhile, same shading area on different shading positions could have different impacts on the identical PV module.展开更多
In this paper some photovoltaic, PV, conversion chains architectures for on-grid applications have been proposed and the advantage of the direct use of a Low Voltage Direct Current (LVDC) bus for the DC loads has been...In this paper some photovoltaic, PV, conversion chains architectures for on-grid applications have been proposed and the advantage of the direct use of a Low Voltage Direct Current (LVDC) bus for the DC loads has been shown. The evaluation of the efficiency of the proposed chains compared to the classical one was performed. It is shown that LVDC use instead of standard AC plugs, in numerous applications, is promising in future. The registered annual saved energy can exceed 25% of the PV generated energy. This important rate, the need of better services at lower economic cost and environmental burden will incite to make reflection about industry and supplies’ future standards.展开更多
This article introduces the history of the reform of on-grid tariff in China, the current status of and currently adopted mechanisms related to on-grid tariffs of coal-fired and renewable energy power generation facil...This article introduces the history of the reform of on-grid tariff in China, the current status of and currently adopted mechanisms related to on-grid tariffs of coal-fired and renewable energy power generation facilities. The article further discusses the proposed and on-going reform and restructure in the electricity price sector, and the trial reforms in regional electricity markets.展开更多
In the light of user-side energy power control requirements, a power control strategy for a household-level EPR based on HES droop control is proposed, focusing on the on-grid, off-grid and seamless switching process....In the light of user-side energy power control requirements, a power control strategy for a household-level EPR based on HES droop control is proposed, focusing on the on-grid, off-grid and seamless switching process. The system operating states are divided based on the DC bus voltage information with one converter used as a slack terminal to stabilize the DC bus voltage and the other converters as power terminals. In the on-grid mode, the GCC and the HES are used as the main control unit to achieve on-grid stable operation, whereas in the off-grid mode, the PV, HES and LC are used as the main control unit at different voltages to achieve stable operation of the island network. Finally, a DC MG system based on a household-level EPR is developed using the PSCAD / EMTDC simulation platform and the results show that the control strategy can effectively adjust the output of each subunit and maintain the stability of the DC bus voltage.展开更多
文摘Because of rich solar resource and low land cost, a lot of large-scale ground-based grid-connected PV systems have been built in Northwest China. In this paper, some shading phenomena on a grid-connected PV system inNorthwest Chinaare classified and analyzed. Through the I-V curve test of PV modules, it can be seen that dust influence system performance of the grid-connected PV system. And the experimental results have shown that shading could affect the electrical properties of PV modules. Meanwhile, same shading area on different shading positions could have different impacts on the identical PV module.
文摘In this paper some photovoltaic, PV, conversion chains architectures for on-grid applications have been proposed and the advantage of the direct use of a Low Voltage Direct Current (LVDC) bus for the DC loads has been shown. The evaluation of the efficiency of the proposed chains compared to the classical one was performed. It is shown that LVDC use instead of standard AC plugs, in numerous applications, is promising in future. The registered annual saved energy can exceed 25% of the PV generated energy. This important rate, the need of better services at lower economic cost and environmental burden will incite to make reflection about industry and supplies’ future standards.
文摘This article introduces the history of the reform of on-grid tariff in China, the current status of and currently adopted mechanisms related to on-grid tariffs of coal-fired and renewable energy power generation facilities. The article further discusses the proposed and on-going reform and restructure in the electricity price sector, and the trial reforms in regional electricity markets.
基金National Key R&D Program of China(2018YFB0905000)Science and Technology Project of State Grid Corporation of China(SGTJDK00DWJS1800232).
文摘In the light of user-side energy power control requirements, a power control strategy for a household-level EPR based on HES droop control is proposed, focusing on the on-grid, off-grid and seamless switching process. The system operating states are divided based on the DC bus voltage information with one converter used as a slack terminal to stabilize the DC bus voltage and the other converters as power terminals. In the on-grid mode, the GCC and the HES are used as the main control unit to achieve on-grid stable operation, whereas in the off-grid mode, the PV, HES and LC are used as the main control unit at different voltages to achieve stable operation of the island network. Finally, a DC MG system based on a household-level EPR is developed using the PSCAD / EMTDC simulation platform and the results show that the control strategy can effectively adjust the output of each subunit and maintain the stability of the DC bus voltage.
