The synchronization phenomenon in nature has been utilized in sensing and timekeeping fields due to its numerous advantages,including amplitude and frequency stabilization,noise reduction,and sensitivity improvement.H...The synchronization phenomenon in nature has been utilized in sensing and timekeeping fields due to its numerous advantages,including amplitude and frequency stabilization,noise reduction,and sensitivity improvement.However,the limited synchronization bandwidth hinders its broader application,and few techniques have been explored to enhance this aspect.In this paper,we conducted theoretical and experimental studies on the unidirectional synchronization characteristics of a resonator with phase lock loop oscillation.A novel enhancement method for the synchronization bandwidth using a parametrically excited MEMS oscillator is proposed,which achieves a remarkably large synchronization bandwidth of 8.85 kHz,covering more than 94%of the hysteresis interval.Importantly,the proposed method exhibits significant potential for high-order synchronization and frequency stabilization compared to the conventional directly excited oscillator.These findings present an effective approach for expanding the synchronization bandwidth,which has promising applications in nonlinear sensing,fully mechanical frequency dividers,and high-precision time references.展开更多
MEMS resonators exhibit rich dynamic behaviors under the internal resonance regime. In this work, we present a novel MEMS bifurcation sensor that exploits frequency unlocking due to a 1:3 internal resonance between tw...MEMS resonators exhibit rich dynamic behaviors under the internal resonance regime. In this work, we present a novel MEMS bifurcation sensor that exploits frequency unlocking due to a 1:3 internal resonance between two electrostatically coupled micro-resonators. The proposed detection mechanism allows the sensor to operate in binary (digital) and analog modes, depending on whether the sensor merely detects a significant jump event in the peak frequency upon unlocking or measures the shift in the peak frequency after unlocking and uses it in conjunction with a calibration curve to estimate the corresponding change in stimulus. We validate the success of this sensor paradigm by experimentally demonstrating charge detection. High charge resolutions are achieved in binary mode, up to 0.137 fC, and in analog mode, up to 0.01 fC. The proposed binary sensor enables extraordinarily high detection resolutions due to the excellent frequency stability under internal resonance and the high signal-to-noise ratio of the shift in peak frequency. Our findings offer new opportunities for high-performance ultrasensitive sensors.展开更多
From flexible interconnection among feeders to hybrid alternating current(AC) and direct current(DC)distribution structures of future smart distribution systems medium-voltage DC distribution centers with flexibly int...From flexible interconnection among feeders to hybrid alternating current(AC) and direct current(DC)distribution structures of future smart distribution systems medium-voltage DC distribution centers with flexibly interlinked multiple microgrids(MGs) will have wide applications on the demand side. A generic coordinated control framework based on a distributed cooperation scheme is proposed for such DC centers, as opposed to centralized control structures. A novel unified control only using local measurements is proposed for these interlinking converters. During normal power disturbances, automatic coordinated power control and mutual support among sub-systems can be realized, thereby improving DC voltage and AC frequency stability to enable multiple MGs to be treated as a real unified cluster. Moreover, with this method, interlinking converters can realize seamless transition in power dispatching mode, common DC bus voltage control mode, and MG support mode without communication and control system switching. A simplified dynamic model has been developed to verify the proposed control strategy. This work is expected to provide a new solution for flexible interconnection and operational control of large-scale MG clusters.展开更多
基金supported by the National Key R&D Program of China(2022YFB3203600)the National Natural Science Foundation of China(52075432)the Program for Innovation Team of Shaanxi Province(No.2021TD-23).
文摘The synchronization phenomenon in nature has been utilized in sensing and timekeeping fields due to its numerous advantages,including amplitude and frequency stabilization,noise reduction,and sensitivity improvement.However,the limited synchronization bandwidth hinders its broader application,and few techniques have been explored to enhance this aspect.In this paper,we conducted theoretical and experimental studies on the unidirectional synchronization characteristics of a resonator with phase lock loop oscillation.A novel enhancement method for the synchronization bandwidth using a parametrically excited MEMS oscillator is proposed,which achieves a remarkably large synchronization bandwidth of 8.85 kHz,covering more than 94%of the hysteresis interval.Importantly,the proposed method exhibits significant potential for high-order synchronization and frequency stabilization compared to the conventional directly excited oscillator.These findings present an effective approach for expanding the synchronization bandwidth,which has promising applications in nonlinear sensing,fully mechanical frequency dividers,and high-precision time references.
基金The authors gratefully acknowledge the support of the National Natural Science Foundation of China(12032015,12102250,12202263)the Science and Technology Innovation Action Plan of Shanghai(21190760100)+1 种基金the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-02-E00030)the China Postdoctoral Science Foundation(2021TQ0201,2022M712069).
文摘MEMS resonators exhibit rich dynamic behaviors under the internal resonance regime. In this work, we present a novel MEMS bifurcation sensor that exploits frequency unlocking due to a 1:3 internal resonance between two electrostatically coupled micro-resonators. The proposed detection mechanism allows the sensor to operate in binary (digital) and analog modes, depending on whether the sensor merely detects a significant jump event in the peak frequency upon unlocking or measures the shift in the peak frequency after unlocking and uses it in conjunction with a calibration curve to estimate the corresponding change in stimulus. We validate the success of this sensor paradigm by experimentally demonstrating charge detection. High charge resolutions are achieved in binary mode, up to 0.137 fC, and in analog mode, up to 0.01 fC. The proposed binary sensor enables extraordinarily high detection resolutions due to the excellent frequency stability under internal resonance and the high signal-to-noise ratio of the shift in peak frequency. Our findings offer new opportunities for high-performance ultrasensitive sensors.
基金supported by National NaturalScience Foundation of China (No. 51507109, No. 51707128)Science and Technology Project of China Southern Power Grid (No. GZKJQQ00000417)
文摘From flexible interconnection among feeders to hybrid alternating current(AC) and direct current(DC)distribution structures of future smart distribution systems medium-voltage DC distribution centers with flexibly interlinked multiple microgrids(MGs) will have wide applications on the demand side. A generic coordinated control framework based on a distributed cooperation scheme is proposed for such DC centers, as opposed to centralized control structures. A novel unified control only using local measurements is proposed for these interlinking converters. During normal power disturbances, automatic coordinated power control and mutual support among sub-systems can be realized, thereby improving DC voltage and AC frequency stability to enable multiple MGs to be treated as a real unified cluster. Moreover, with this method, interlinking converters can realize seamless transition in power dispatching mode, common DC bus voltage control mode, and MG support mode without communication and control system switching. A simplified dynamic model has been developed to verify the proposed control strategy. This work is expected to provide a new solution for flexible interconnection and operational control of large-scale MG clusters.
