Model Predictive Control for Dual Active Bridge in Naval DC Microgrids Supplying Pulsed Power Loads Featuring Fast Transition and Online Transformer Current Minimization

Pulsed power loads (PPLs) are commonly incorporated in medium voltage dc microgrids on naval vessels. To mitigate their detrimental effects, dedicated energy storage systems can be installed and their converters need to have excellent disturbance rejection capability. To facilitate this objective, a moving-discretized-control-set model-predictive-control (MDCS-MPC) is proposed in this letter and applied on a dual-active-bridge converter. Fixed switching frequency is maintained, enabling easy passive components design. The proposed MDCS-MPC has a small number of calculating points in each switching period, which enables the implementation in standard commercial control platforms. The operating principle of the MDCS-MPC is introduced in development of a cost function that, on one hand, provides stiff voltage regulation; on the other hand, minimizes transformer current stress online. Theoretical claims are verified on a 20 kHz 1 kW dual active bridge

An efficient power plant model of electric vehicles for unit commitment of large scale wind farms

AbstractAn efficient power plant model of electric vehicles (E-EPP) considering the travelling comfort levels of EV users is developed to investigate the contribution of EVs on the unit commitment (UC) of large scale wind farms. Firstly, a generic EV battery model (GEBM) is established considering the uncertainties of battery parameters. Then, a Monte Carlo Simulation (MCS) method is implemented within the E-EPP to obtain the available response capacity of EV charging load over time. And a UC strategy using the E-EPP based on power flow tracing is developed. Finally, a modified IEEE 118-bus system integrated with wind farms is used to verify the effectiveness of the E-EPP for the UC of large scale wind farms

Probe system design for three dimensional micro/nano scratching machine

This paper presents the design and testing methodologies for a probe system used in a tip-based three dimensional micro/nano scratching machine. The probe system is one of the most important components of the scratching machine, including an electromagnetic device and a probe suspension mechanism. The electromagnetic device is used to generate electromagnetic force to drive the probe suspension mechanism, and further scratch the sample. The probe suspension mechanism is utilized to support the diamond probe and form the capacitor plates with the aluminum film. Both analytical modeling and finite element analysis are conducted to improve the static and dynamic characteristics of the proposed scratching machine. A prototype has been developed to validate the established design methodologies. A number of experimental tests have been conducted to examine the prototype performance. From the experimental results, it is noted that the developed probe system has a force resolution of 78.4 μN, a displacement resolution of 60 nm, and the first natural frequency of 465 Hz. This indicates that it can be used for the development of the three dimensional submicron or even nano scratching

Comparative Study of the Amount of Re-released Hemoglobin from α-Thalassemia and Hereditary Spherocytosis Erythrocytes

Hemoglobin release test (HRT), which is established by our lab, is a new experiment to observe the re-released hemoglobin (Hb) from erythrocytes. In this study, one-dimension HRT, double dimension HRT, and isotonic and hypotonic HRT were performed to observe the re-released Hb from the blood samples of normal adult, hereditary spherocytosis (HS), and α-thalassemia. The results showed that compared with normal adult, the re-released Hb from HS blood sample was decreased significantly; however, the re-released Hb from α-thalassemia blood sample was increased significantly. The mechanism of this phenomenon was speculated to have relation with the abnormal amount of membrane-binding Hb

The Equivalent Thermal Parameter Model and Simulation of Air Conditioner System in Demand Response Programs

AbstractEstimating end-use energy consumption that accurately reflects the variance of the end-load is critical for the grid wise simulation and analysis work. In a house, the largest load with a thermal cycle is often the heating ventilation and air conditioning (HVAC) system. So the thermal dynamics of typical residential electric air conditioner is discussed, and then an equivalent thermal parameters (ETP) model is built by the thermal equilibrium in this paper. Based on this, the switch status, indoor air temperature and power consumption are simulated through control strategies of constant thermostat set point. The results show according the switch status, indoor air temperature can be calculated by the ETP model, thus give the desire status to the grid according the setting temperature. In summer, with the increasing of setting temperature, the frequency of on-off becomes lower, thus the power consumption also reduces from 1200kW (26°C) to 970kW (27°C). So if some control strategies are used, the model will play an important part on decreasing the peak-average rate of the power grid and also improving the load rate of grid