A novel transient rotor current control scheme is proposed in this paper for a doubly-fed induction generator（DFIG）equipped with a superconducting magnetic energy storage（SMES） device to enhance its transient volt...A novel transient rotor current control scheme is proposed in this paper for a doubly-fed induction generator（DFIG）equipped with a superconducting magnetic energy storage（SMES） device to enhance its transient voltage and frequency support capacity during grid faults. The SMES connected to the DC-link capacitor of the DFIG is controlled to regulate the transient dc-link voltage so that the whole capacity of the grid side converter（GSC） is dedicated to injecting reactive power to the grid for the transient voltage support. However, the rotor-side converter（RSC） has different control tasks for different periods of the grid fault. Firstly, for Period I, the RSC injects the demagnetizing current to ensure the controllability of the rotor voltage. Then, since the dc stator flux degenerates rapidly in Period II, the required demagnetizing current is low in Period II and the RSC uses the spare capacity to additionally generate the reactive（priority） and active current so that the transient voltage capability is corroborated and the DFIG also positively responds to the system frequency dynamic at the earliest time. Finally, a small amount of demagnetizing current is provided after the fault clearance. Most of the RSC capacity is used to inject the active current to further support the frequency recovery of the system. Simulations are carried out on a simple power system with a wind farm. Comparisons with other commonly used control methods are performed to validate the proposed control method.展开更多
针对构网型变流器(grid-forming voltage source converter,GFM-VSC)系统在大扰动下暂态稳定问题,现有研究未能充分考虑电力电子电源暂态快速响应与控制可塑的特点。为此,以GFM-VSC为对象,借助等面积法原理与相平面图法,从能量角度揭示...针对构网型变流器(grid-forming voltage source converter,GFM-VSC)系统在大扰动下暂态稳定问题,现有研究未能充分考虑电力电子电源暂态快速响应与控制可塑的特点。为此,以GFM-VSC为对象,借助等面积法原理与相平面图法,从能量角度揭示了其暂态响应机制与传统同步机系统的差异,分析了控制塑造下GFM-VSC系统的暂态稳定机理;然后,针对大扰动下易于触发的限幅环节,分析了系统无法自主退出限幅而失稳的机制,并提出了附带电流分配系数的改进限幅策略,有效增强了系统暂态稳定性。最后,通过仿真验证了理论分析与改进方法的正确性。展开更多
A transient performance optimized CCL-LDO regulator is proposed.In the CCL-LDO,the control method of the charge pump phase-locked loop is adopted.A current control loop has the feedback signal and reference current to...A transient performance optimized CCL-LDO regulator is proposed.In the CCL-LDO,the control method of the charge pump phase-locked loop is adopted.A current control loop has the feedback signal and reference current to be compared,and then a loop filter generates the gate voltage of the power MOSFET by integrating the error current.The CCL-LDO has the optimized damping coefficient and natural resonant frequency, while its output voltage can be sub-l-V and is not restricted by the reference voltage.With a 1μF decoupling capacitor,the experimental results based on a 0.13μm CMOS process show that the output voltage is 1.0 V;when the workload changes from 100μA to 100 mA transiently,the stable dropout is 4.25 mV,the settling time is 8.2μs and the undershoot is 5.11 mV;when the workload changes from 100 mA to 100μA transiently,the stable dropout is 4.25 mV,the settling time is 23.3μs and the overshoot is 6.21 mV.The PSRR value is more than -95 dB.Most of the attributes of the CCL-LDO are improved rapidly with a FOM value of 0.0097.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51307124)the Major Program of the National Natural Science Foundation of China(Grant No.51190105)
文摘A novel transient rotor current control scheme is proposed in this paper for a doubly-fed induction generator（DFIG）equipped with a superconducting magnetic energy storage（SMES） device to enhance its transient voltage and frequency support capacity during grid faults. The SMES connected to the DC-link capacitor of the DFIG is controlled to regulate the transient dc-link voltage so that the whole capacity of the grid side converter（GSC） is dedicated to injecting reactive power to the grid for the transient voltage support. However, the rotor-side converter（RSC） has different control tasks for different periods of the grid fault. Firstly, for Period I, the RSC injects the demagnetizing current to ensure the controllability of the rotor voltage. Then, since the dc stator flux degenerates rapidly in Period II, the required demagnetizing current is low in Period II and the RSC uses the spare capacity to additionally generate the reactive（priority） and active current so that the transient voltage capability is corroborated and the DFIG also positively responds to the system frequency dynamic at the earliest time. Finally, a small amount of demagnetizing current is provided after the fault clearance. Most of the RSC capacity is used to inject the active current to further support the frequency recovery of the system. Simulations are carried out on a simple power system with a wind farm. Comparisons with other commonly used control methods are performed to validate the proposed control method.
文摘针对构网型变流器(grid-forming voltage source converter,GFM-VSC)系统在大扰动下暂态稳定问题,现有研究未能充分考虑电力电子电源暂态快速响应与控制可塑的特点。为此,以GFM-VSC为对象,借助等面积法原理与相平面图法,从能量角度揭示了其暂态响应机制与传统同步机系统的差异,分析了控制塑造下GFM-VSC系统的暂态稳定机理;然后,针对大扰动下易于触发的限幅环节,分析了系统无法自主退出限幅而失稳的机制,并提出了附带电流分配系数的改进限幅策略,有效增强了系统暂态稳定性。最后,通过仿真验证了理论分析与改进方法的正确性。
基金Project supported by the National New Century Excellent Talents in Universitythe Program for Changjiang Scholars and Innovative Research Team in University of Chinathe National Natural Science Foundation of China(Nos.61076036,60906009)
文摘A transient performance optimized CCL-LDO regulator is proposed.In the CCL-LDO,the control method of the charge pump phase-locked loop is adopted.A current control loop has the feedback signal and reference current to be compared,and then a loop filter generates the gate voltage of the power MOSFET by integrating the error current.The CCL-LDO has the optimized damping coefficient and natural resonant frequency, while its output voltage can be sub-l-V and is not restricted by the reference voltage.With a 1μF decoupling capacitor,the experimental results based on a 0.13μm CMOS process show that the output voltage is 1.0 V;when the workload changes from 100μA to 100 mA transiently,the stable dropout is 4.25 mV,the settling time is 8.2μs and the undershoot is 5.11 mV;when the workload changes from 100 mA to 100μA transiently,the stable dropout is 4.25 mV,the settling time is 23.3μs and the overshoot is 6.21 mV.The PSRR value is more than -95 dB.Most of the attributes of the CCL-LDO are improved rapidly with a FOM value of 0.0097.
