A 2.7-4.0 GHz dual-mode auto frequency calibration(AFC) fast locking PLL was designed for navigation system on chip(SoC). The SoC was composed of one radio frequency(RF) receiver, one baseband and several system contr...A 2.7-4.0 GHz dual-mode auto frequency calibration(AFC) fast locking PLL was designed for navigation system on chip(SoC). The SoC was composed of one radio frequency(RF) receiver, one baseband and several system control parts. In the proposed AFC block, both analog and digital modes were designed to complete the AFC process. In analog mode, the analog part sampled and detected the charge pump output tuning voltage, which would give the indicator to digital part to adjust the voltage control oscillator(VCO) capacitor bank. In digital mode, the digital part counted the phase lock loop(PLL) divided clock to judge whether VCO frequency was fast or slow. The analog and digital modes completed the auto frequency calibration function independently by internal switch. By designing a special switching algorithm, the switch of the digital and analog mode could be realized anytime during the lock and unlock detecting process for faster and more stable locking. This chip is fabricated in 0.13 μm RF complementary metal oxide semiconductor(CMOS) process, and the VCO supports the frequency range from 2.7 to 4.0 GHz. Tested 3.96 GHz frequency phase noise is -90 d Bc/Hz@100 k Hz frequency offset and -120 d Bc/Hz@1 MHz frequency offset. By using the analog mode in lock detection and digital mode in unlock detection, tested AFC time is less than 9 μs and the total PLL lock time is less than 19 μs. The SoC acquisition and tracking sensitivity are about-142 d Bm and-155 d Bm, respectively. The area of the proposed PLL is 0.35 mm^2 and the total SoC area is about 9.6 mm^2.展开更多
为解决孤岛模式下交直流混合微电网稳定运行的问题,文中提出一种孤岛交直流混合微电网柔性多状态开关(soft normally open point, SNOP)统一下垂控制策略。该策略基于系统功率平衡关系,通过归一化方法将2条馈线的频率下垂特性和直流电...为解决孤岛模式下交直流混合微电网稳定运行的问题,文中提出一种孤岛交直流混合微电网柔性多状态开关(soft normally open point, SNOP)统一下垂控制策略。该策略基于系统功率平衡关系,通过归一化方法将2条馈线的频率下垂特性和直流电压下垂特性相结合,根据交流频率和直流电压的变化情况,判断系统的运行状态,并通过SNOP统一调节交流子网频率和直流子网电压,使交、直流微电网能够均衡承担系统总功率变化量,从而确保交流频率和直流电压稳定在系统允许范围内。同时,为了优先确保分布式电源的就近消纳,避免SNOP的非必要动作,设计了SNOP的调节死区,使得交、直流微电网能够优先利用各子网内分布式电源,从而减少SNOP交、直流侧功率的频繁交互。最后,通过MATLAB/Simulink仿真验证了所提统一下垂控制策略的有效性。展开更多
利用柔性直流输电系统潜在的调频能力,可实现对电网频率的有效支撑。但在传统调频过程中,由于虚拟惯量的增加降低了系统对参考功率的跟踪速度,同时带来电压控制稳定裕度的降低,弱化了系统的频率支撑能力。因此,提出一种计及电压的参数...利用柔性直流输电系统潜在的调频能力,可实现对电网频率的有效支撑。但在传统调频过程中,由于虚拟惯量的增加降低了系统对参考功率的跟踪速度,同时带来电压控制稳定裕度的降低,弱化了系统的频率支撑能力。因此,提出一种计及电压的参数解耦虚拟同步发电机(virtual synchronous generator,VSG)策略。首先,对换流站辅助频率控制模型及常规VSG控制方式进行分析,引入直流母线电压,并采用带下垂的PI控制器对电压偏差进行调节。然后,对部分有功功率控制回路(active power loop,APL)进行改进,引入低通滤波器及前馈回路消除VSG固有的振荡极点,将APL的参考功率跟踪速度和VSG可提供的虚拟惯量支撑能力进行解耦。最后,利用Matlab/Simulink仿真对所提策略进行仿真验证。结果表明,所提策略能将虚拟惯量的调节和参考功率的跟踪由两参数独立控制,使控制方式更加灵活,并有效提高换流站的频率支撑能力,同时也保证了对电压的良好控制效果。展开更多
基金Project(2011912004)supported by the Major Program of the Economic & Information Commission Program of Guangdong Province,ChinaProjects(2011B010700065,2011A090200106)supported by the Major Program of the Department of Science and Technology of Guangdong Province,China
文摘A 2.7-4.0 GHz dual-mode auto frequency calibration(AFC) fast locking PLL was designed for navigation system on chip(SoC). The SoC was composed of one radio frequency(RF) receiver, one baseband and several system control parts. In the proposed AFC block, both analog and digital modes were designed to complete the AFC process. In analog mode, the analog part sampled and detected the charge pump output tuning voltage, which would give the indicator to digital part to adjust the voltage control oscillator(VCO) capacitor bank. In digital mode, the digital part counted the phase lock loop(PLL) divided clock to judge whether VCO frequency was fast or slow. The analog and digital modes completed the auto frequency calibration function independently by internal switch. By designing a special switching algorithm, the switch of the digital and analog mode could be realized anytime during the lock and unlock detecting process for faster and more stable locking. This chip is fabricated in 0.13 μm RF complementary metal oxide semiconductor(CMOS) process, and the VCO supports the frequency range from 2.7 to 4.0 GHz. Tested 3.96 GHz frequency phase noise is -90 d Bc/Hz@100 k Hz frequency offset and -120 d Bc/Hz@1 MHz frequency offset. By using the analog mode in lock detection and digital mode in unlock detection, tested AFC time is less than 9 μs and the total PLL lock time is less than 19 μs. The SoC acquisition and tracking sensitivity are about-142 d Bm and-155 d Bm, respectively. The area of the proposed PLL is 0.35 mm^2 and the total SoC area is about 9.6 mm^2.
文摘为解决孤岛模式下交直流混合微电网稳定运行的问题,文中提出一种孤岛交直流混合微电网柔性多状态开关(soft normally open point, SNOP)统一下垂控制策略。该策略基于系统功率平衡关系,通过归一化方法将2条馈线的频率下垂特性和直流电压下垂特性相结合,根据交流频率和直流电压的变化情况,判断系统的运行状态,并通过SNOP统一调节交流子网频率和直流子网电压,使交、直流微电网能够均衡承担系统总功率变化量,从而确保交流频率和直流电压稳定在系统允许范围内。同时,为了优先确保分布式电源的就近消纳,避免SNOP的非必要动作,设计了SNOP的调节死区,使得交、直流微电网能够优先利用各子网内分布式电源,从而减少SNOP交、直流侧功率的频繁交互。最后,通过MATLAB/Simulink仿真验证了所提统一下垂控制策略的有效性。
文摘利用柔性直流输电系统潜在的调频能力,可实现对电网频率的有效支撑。但在传统调频过程中,由于虚拟惯量的增加降低了系统对参考功率的跟踪速度,同时带来电压控制稳定裕度的降低,弱化了系统的频率支撑能力。因此,提出一种计及电压的参数解耦虚拟同步发电机(virtual synchronous generator,VSG)策略。首先,对换流站辅助频率控制模型及常规VSG控制方式进行分析,引入直流母线电压,并采用带下垂的PI控制器对电压偏差进行调节。然后,对部分有功功率控制回路(active power loop,APL)进行改进,引入低通滤波器及前馈回路消除VSG固有的振荡极点,将APL的参考功率跟踪速度和VSG可提供的虚拟惯量支撑能力进行解耦。最后,利用Matlab/Simulink仿真对所提策略进行仿真验证。结果表明,所提策略能将虚拟惯量的调节和参考功率的跟踪由两参数独立控制,使控制方式更加灵活,并有效提高换流站的频率支撑能力,同时也保证了对电压的良好控制效果。
