The China Fusion Engineering Test Reactor plans to build a 200 k V/25 A acceleration grid power supply(AGPS)for the negative-ion-based neutral beam injector prototype system.The AGPS uses a rectifier-inverter-isolated...The China Fusion Engineering Test Reactor plans to build a 200 k V/25 A acceleration grid power supply(AGPS)for the negative-ion-based neutral beam injector prototype system.The AGPS uses a rectifier-inverter-isolated step-up structure.There is a DC bus between the rectifier and the inverter.In order to limit DC bus voltage ripple and transient fluctuations,a large number of capacitors are used,which degrades the reliability of the power supply and occupies a large amount of space.This work finds that due to the difference in the turn-off time of the rectifier and the inverter,the capacitance mainly depends on the rectifier current when the inverter is turned off.On this basis,an active power filter(APF)scheme is proposed to absorb the current.To enhance the dynamic response ability of the APF,model predictive control is adopted.In this paper,the circuit structure of the APF is introduced,the prediction model is deduced,the corresponding control strategy and signal detection method are proposed,and the simulation and experimental results show that APF can track the transient current of the DC bus and reduce the voltage fluctuation significantly.展开更多
In this paper, model-predictive control(MPC) is proposed for controlling power source of accelerators. The system state equation is employed as the predictive model. With MPC, the difference between possible output an...In this paper, model-predictive control(MPC) is proposed for controlling power source of accelerators. The system state equation is employed as the predictive model. With MPC, the difference between possible output and the ideal output is forecasted and decreased, so that the system can trace the ideal trail as closely and quickly as possible. The results of simulations and experiments show that this method can reduce influence of low frequency noise.展开更多
The utilization of renewable energy in sending-end power grids is increasing rapidly,which brings difficulties to voltage control.This paper proposes a coordinated voltage control strategy based on model predictive co...The utilization of renewable energy in sending-end power grids is increasing rapidly,which brings difficulties to voltage control.This paper proposes a coordinated voltage control strategy based on model predictive control(MPC)for the renewable energy power plants of wind and solar power connected to a weak sending-end power grid(WSPG).Wind turbine generators(WTGs),photovoltaic arrays(PVAs),and a static synchronous compensator are coordinated to maintain voltage within a feasible range during operation.This results in the full use of the reactive power capability of WTGs and PVAs.In addition,the impact of the active power outputs of WTGs and PVAs on voltage control are considered because of the high R/X ratio of a collector system.An analytical method is used for calculating sensitivity coefficients to improve computation efficiency.A renewable energy power plant with 80 WTGs and 20 PVAs connected to a WSPG is used to verify the proposed voltage control strategy.Case studies show that the coordinated voltage control strategy can achieve good voltage control performance,which improves the voltage quality of the entire power plant.展开更多
为保证全直流风电系统安全并网运行,系统直流电压稳定控制至关重要。全直流风电系统直流电压稳定控制采用比例积分(PI)控制时,PI参数较多且整定繁琐复杂,在非正常运行工况下动态响应速度相对较慢,控制精度不够高。针对以上问题,文章提...为保证全直流风电系统安全并网运行,系统直流电压稳定控制至关重要。全直流风电系统直流电压稳定控制采用比例积分(PI)控制时,PI参数较多且整定繁琐复杂,在非正常运行工况下动态响应速度相对较慢,控制精度不够高。针对以上问题,文章提出一种基于有限控制集模型预测控制(Finite Control Set-Model Predictive Control,FCS-MPC)原理对系统换流器桥臂晶体管开关状态进行控制的系统直流电压稳定控制策略。该策略结合机侧整流器及并网逆变器的电流预测模型,以换流器输出电流为控制变量构造代价函数,以代价函数为优化目标,为避免计算时延导致的控制延时,引入延时补偿提高控制准确度,并引入权重系数实现多目标优化,通过遍历计算产生最优开关组合信号触发换流器。在Matlab/Simulink中建立全直流风电系统的仿真模型,在不同工况下,对所提策略与传统PI控制进行对比仿真分析,仿真结果有效验证了所提控制策略的静态性能及动态性能。展开更多
基金supported in part by the National Key Research and Development Program of China(No.2017YFE0300104)in part by National Natural Science Foundation of China(No.51821005)。
文摘The China Fusion Engineering Test Reactor plans to build a 200 k V/25 A acceleration grid power supply(AGPS)for the negative-ion-based neutral beam injector prototype system.The AGPS uses a rectifier-inverter-isolated step-up structure.There is a DC bus between the rectifier and the inverter.In order to limit DC bus voltage ripple and transient fluctuations,a large number of capacitors are used,which degrades the reliability of the power supply and occupies a large amount of space.This work finds that due to the difference in the turn-off time of the rectifier and the inverter,the capacitance mainly depends on the rectifier current when the inverter is turned off.On this basis,an active power filter(APF)scheme is proposed to absorb the current.To enhance the dynamic response ability of the APF,model predictive control is adopted.In this paper,the circuit structure of the APF is introduced,the prediction model is deduced,the corresponding control strategy and signal detection method are proposed,and the simulation and experimental results show that APF can track the transient current of the DC bus and reduce the voltage fluctuation significantly.
基金Supported by National Natural Science Foundation of China(No.11027508)
文摘In this paper, model-predictive control(MPC) is proposed for controlling power source of accelerators. The system state equation is employed as the predictive model. With MPC, the difference between possible output and the ideal output is forecasted and decreased, so that the system can trace the ideal trail as closely and quickly as possible. The results of simulations and experiments show that this method can reduce influence of low frequency noise.
基金supported by National Natural Science Foundation Joint Key Project of China(2016YFB0900900).
文摘The utilization of renewable energy in sending-end power grids is increasing rapidly,which brings difficulties to voltage control.This paper proposes a coordinated voltage control strategy based on model predictive control(MPC)for the renewable energy power plants of wind and solar power connected to a weak sending-end power grid(WSPG).Wind turbine generators(WTGs),photovoltaic arrays(PVAs),and a static synchronous compensator are coordinated to maintain voltage within a feasible range during operation.This results in the full use of the reactive power capability of WTGs and PVAs.In addition,the impact of the active power outputs of WTGs and PVAs on voltage control are considered because of the high R/X ratio of a collector system.An analytical method is used for calculating sensitivity coefficients to improve computation efficiency.A renewable energy power plant with 80 WTGs and 20 PVAs connected to a WSPG is used to verify the proposed voltage control strategy.Case studies show that the coordinated voltage control strategy can achieve good voltage control performance,which improves the voltage quality of the entire power plant.
文摘为保证全直流风电系统安全并网运行,系统直流电压稳定控制至关重要。全直流风电系统直流电压稳定控制采用比例积分(PI)控制时,PI参数较多且整定繁琐复杂,在非正常运行工况下动态响应速度相对较慢,控制精度不够高。针对以上问题,文章提出一种基于有限控制集模型预测控制(Finite Control Set-Model Predictive Control,FCS-MPC)原理对系统换流器桥臂晶体管开关状态进行控制的系统直流电压稳定控制策略。该策略结合机侧整流器及并网逆变器的电流预测模型,以换流器输出电流为控制变量构造代价函数,以代价函数为优化目标,为避免计算时延导致的控制延时,引入延时补偿提高控制准确度,并引入权重系数实现多目标优化,通过遍历计算产生最优开关组合信号触发换流器。在Matlab/Simulink中建立全直流风电系统的仿真模型,在不同工况下,对所提策略与传统PI控制进行对比仿真分析,仿真结果有效验证了所提控制策略的静态性能及动态性能。
