The performance of photovoltaic(PV)modules is affected by environmental factors such as irradiance and temperature,which can lead to a decrease in output performance or even damage.This study proposes an improved form...The performance of photovoltaic(PV)modules is affected by environmental factors such as irradiance and temperature,which can lead to a decrease in output performance or even damage.This study proposes an improved formula for calculating the real maximum power of PV modules by analysing the influence of irradiance and temperature.A simulation model is developed using PLECS software to simulate the global maximum power of PV modules under different environmental conditions and the results are compared with the calculated real maximum power.A power optimization scheme for PV modules is then proposed based on current equalization and constant voltage control.This scheme employs a single-switch multi-winding forward-flyback converter to equalize the mismatched currents between cell strings,thereby enhancing the output performance.Traditional proportional-integral controllers are utilized to achieve constant voltage control and obtain the real maximum power of PV modules.Simulation models are built in the PLECS simulation platform to evaluate the performance of a global maximum power point tracking scheme based on the traditional perturb-and-observe(TPO)algorithm with current equalization,a segment perturb-and-observe algorithm without current equalization,and the proposed power optimization scheme.The simulation results demonstrate that the proposed constant voltage control has greater efficiency than the TPO algorithm.The proposed scheme achieves a significant improvement in efficiency,with a 27.87%increase compared with the segment perturb-and-observe algorithm without current equalization.展开更多
The highpower pulsed power supply system for the magnetic field of the HL-2A Tokamak is described in this paper. The total output power of its eight magnetic field power supply units of nearly 250 MW. Their highest DC...The highpower pulsed power supply system for the magnetic field of the HL-2A Tokamak is described in this paper. The total output power of its eight magnetic field power supply units of nearly 250 MW. Their highest DC output voltage and current are 3510 V and 45 kA, respectively. All the units are operated in a pulsed mode. The pulse duration is 5 s, and the cyclic period is 15 min. The power supply system consists mainly of pulsed flywheel motor generators, rectifying transformers, thyristor converters, diode rectifiers and switches. The system incorporates many key technologies-supply equalization with two generators and four diode bridges, constant-angle phase triggers with a wide frequency range, current equalization, a status detector for the high current 6-phase converter, and advanced monitoring based on a programmable logic computer and engineering parameter measurement. The experimental results show that the performance of the power supply system satisfies the requirements of HL-2A experiments very well.展开更多
文摘The performance of photovoltaic(PV)modules is affected by environmental factors such as irradiance and temperature,which can lead to a decrease in output performance or even damage.This study proposes an improved formula for calculating the real maximum power of PV modules by analysing the influence of irradiance and temperature.A simulation model is developed using PLECS software to simulate the global maximum power of PV modules under different environmental conditions and the results are compared with the calculated real maximum power.A power optimization scheme for PV modules is then proposed based on current equalization and constant voltage control.This scheme employs a single-switch multi-winding forward-flyback converter to equalize the mismatched currents between cell strings,thereby enhancing the output performance.Traditional proportional-integral controllers are utilized to achieve constant voltage control and obtain the real maximum power of PV modules.Simulation models are built in the PLECS simulation platform to evaluate the performance of a global maximum power point tracking scheme based on the traditional perturb-and-observe(TPO)algorithm with current equalization,a segment perturb-and-observe algorithm without current equalization,and the proposed power optimization scheme.The simulation results demonstrate that the proposed constant voltage control has greater efficiency than the TPO algorithm.The proposed scheme achieves a significant improvement in efficiency,with a 27.87%increase compared with the segment perturb-and-observe algorithm without current equalization.
文摘The highpower pulsed power supply system for the magnetic field of the HL-2A Tokamak is described in this paper. The total output power of its eight magnetic field power supply units of nearly 250 MW. Their highest DC output voltage and current are 3510 V and 45 kA, respectively. All the units are operated in a pulsed mode. The pulse duration is 5 s, and the cyclic period is 15 min. The power supply system consists mainly of pulsed flywheel motor generators, rectifying transformers, thyristor converters, diode rectifiers and switches. The system incorporates many key technologies-supply equalization with two generators and four diode bridges, constant-angle phase triggers with a wide frequency range, current equalization, a status detector for the high current 6-phase converter, and advanced monitoring based on a programmable logic computer and engineering parameter measurement. The experimental results show that the performance of the power supply system satisfies the requirements of HL-2A experiments very well.
