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Since the capacitor equivalent series resistance (ESR) above 1kHz almost stays constant, dc-link current root-mean-square (RMS) closed form equation is an easy way to evaluate the capacitor losses from the switching harmonic currents (SHCs). But when the ac current contains multiple low order harmonics (LOHs), their impacts on the dc-link has not been systematically studied. In this paper, a straightforward...
Hybrid excited flux-switching machine (HEFS) is a novel brushless synchronous motor. Compared to conventional permanent magnet synchronous machine (PMSM) and permanent magnet flux switching (PMFS) machine, it has additional excitation winding in its stator to modulate the air-gap magnet field. In this paper, the topology and operating principle of HEFS is analyzed. Its dynamic mathematical models...
To manage the microgrid effectively, it is important to get the power information among multiple distributed generation (DG) units. However, when the droop control method is adopted, as the corresponding DG units cannot be simply modeled as VF or PQ buses, the conventional power flow algorithm may become inapplicable. To solve this issue, a time domain iteration (TDI) based power flow algorithm is...
Entry guidance of a high-lifting vehicle is a complex problem that has attracted the attention of researchers around the world for many years. This paper classifies the previous studies into two categories: trajectory planning-tracking method (TPTM) and predictor-corrector method (PCM). A new trajectory planning method based on the dynamic pressure profile of the vehicle is proposed in this paper...
A predictor-corrector entry guidance method satisfying the constraints of no-fly zone and waypoint is proposed in this paper. First, Gauss pseudospectral method is used to generate a reference trajectory. Based on the reference trajectory some reference points are selected which partition the entry process into several subsections. Then a predictor-corrector guidance law is developed. The trajectory...
Compared with executing Network Functions (NFs) on dedicated hardwares, the recent trend of Network Function Virtualization (NFV) holds the promise for operators to flexibly deploy software-based NFs on commodity servers. However, virtual NFs (VNFs) are normally "chained" together to provide a specific network service. Thus, an efficient scheme is needed to place the VNF chains across the...
A system reliability analysis method based on system functional model is presented for the limitations of existing reliability modeling and assessment methods which have difficulties in reliability modeling, especially for complex systems. System function failure model is established firstly, and then the minimum cut sets are obtained through the fault simulation. System task reliability can be calculated...
Wake vortex is a kind of largely-scaled distributed complex objects, and its radar scattering characteristics are very difficult to analysis. Generally, wake vortex can be classified into two categories in terms of weather conditions: clear air condition and precipitation condition (fog, rain, snow). Different wake vortices have different scattering mechanisms and characteristics. This paper presents...
KeeLoq is a 528-round lightweight block cipher which has a 64-bit secret key and a 32-bit block length. The cube attack, proposed by Dinur and Shamir, is a new type of attacking method. In this paper, we investigate the security of KeeLoq against iterative side-channel cube attack which is an enhanced attack scheme. Based on structure of typical block ciphers, we give the model of iterative side-channel...
In complex and data-intensive applications, data scheduling between data centers must occur when multiple datasets stored in distributed data centers are processed by one computation. To store massive datasets effectively and reduce data scheduling between data centers during the execution of computations, a mathematical model of data scheduling between data centers in cloud computing is built and...
The Co-simulation of Saber and Simulink is raised in the automotive electronic throttle control system reliability analysis aiming to model sharing of different simulation software. The principle of co-simulation, general process and the method of parameter setting are introduced based on Saber and Simulink. The co-simulation of electronic throttle control system describes process realization of co-simulation,...
Since the Pneumatic Force Actuator System with Long Tubes (PFASWLT) possesses the characteristics of strong nonlinearity, time delay and uncertainties due to the changeable load and environmental parameters, it is difficult to identify parameters of the dynamical process and establish the precise mathematical model. The Model-Free Adaptive Control (MFAC) is a senior control method and there is no...
Energy storage (ES) station can be dispatched by the energy management system (EMS) to realize peak load shifting, frequency regulation and other system control. According to the dispatch instructions, total charging and discharging power is allocated among all energy storage units reasonably and optimally. In this paper, a power allocation method is proposed. According to the performance parameters...
The pneumatic servo system is used more and more widely in industrial production because of its advantages like low cost, easy maintenance and environmental cleaning. However, due to the compressibility of gases, the nonlinear of the flow rate through valves, and the friction between the piston and the cylinder, the precise control of the pneumatic servo system has many difficulties. Among them, the...
At present, the research of robots imitating water strider is mainly focusing on imitating the skating movement of the insects. In contrast, the jumping motion of water striders needs a sufficiently large driving force to lift the body detaching from the water surface, which is easy to break the hydrophobic property of the material and result in the sinking of the robot, so there is few research on...
Ultrasonic leak detection technology is growing along with the industry and production of emerging technologies. We proposes a way of measurement of leaking gas with the help of ultrasonic transducer, which is based on the fact that turbulence generated by compressed gas leaking from small hole will produce ultrasonic wave. This research based on principle of tiny gas leakage produced by weak differential...
To ensure safe ship navigation, true water depths should be deep enough with respect to the corresponding depths on a chart. Therefore, a set of basic quality indices, including an index of the probability of adequate depth, were developed to evaluate the quality of a digital depth model (DDM) with respect to navigational safety. In addition, these methods are proposed for assessing the probability...
The integration of renewable energies requests smart power grids to be capable of supporting various power flow patterns, and thus urgently needs the development of smart and robust power flow solvers. However, there are several great challenges, as the problem of power flow divergence and the issue of multi-solution. Homotopy methodology is commonly utilized to deal with these issues. This paper...
Received Signal Strength (RSS) and Round Trip Time (RTT) are two common metrics for a wireless receiver to tell the proximity of a remote wireless transmitter. A large RSS or a small RTT normally indicates a close transmitter, and vice versa. Both metrics are effective in a benign environment. However, when the transmitter modifies the send time or transmit power to hide its real distance, they may...
To solve the detection of rotor position and speed of brushless DC (BLDC) motors in sensor-less position control system, an improved estimation method of rotor position and speed based on nonsingular fast terminal sliding mode and high order sliding mode observer is proposed. The results of simulation illustrate that the developed hybrid sliding mode observer can accurately estimate the rotor speed...
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