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This paper proposes an implementation of an on-line maximum efficiency control for matrix-converter based IPMSM drive systems. A simplified efficiency model of the drive system is established first; as a result, the detailed model of the inverter loss and motor loss is not required. Next, by on-line searching the maximum efficiency operating point, the efficiency of the whole drive system can be significantly...
We developed Tactile Imaging System (TIS), which measures mechanical properties of tissue inclusions. The functional components of TIS include: a monochrome camera, a soft and transparent silicone probe, and an LED illumination circuit. The deformation of the soft TIS probe is used to evaluate size and compliance of inclusions, which is the inverse of elastic modulus. TIS algorithm development and...
This paper proposes a sensorless matrix-converter IPMSM drive system based on detecting the PWM switching-state current-ripples. By detecting the current-ripple of each PWM switching-state, the rotor position of the IPMSM can be estimated. As a result, the circuit of high-frequency sinusoidal voltage or current source is not required. A nonlinear controller is proposed here. The proposed nonlinear...
Based on the optimal primary and secondary pole number combination selection rule of linear switched-flux PM machines (LSFPMM), the C-core and E-core LSFPMM with even primary poles has been proposed, which are optimized by individual parameter optimization. The results of individual parameter optimization with different secondary pole numbers are investigated and compared based on 2D finite element...
This paper proposes an improved sensorless matrix-converter IPMSM drive system using a high frequency injection method. By suitably choosing different virtual dc-bus voltages and compensating the duty cycle of the switching states, the estimated position error can be obviously reduced. A 32-bit digital signal processor, TMS-320LF-2407A, is used to execute the rotor position estimation and the whole...
We propose a modified no-switching continuous-variable quantum key distribution protocol to improve the secret key rate and maximum transmission distance by inserting a noiseless linear amplifier at the output of quantum channel. Security analysis shows that a noiseless linear amplifier with gain g can increase the maximum transmission distance of no-switching protocol by 100log10g km
A novel family of loss-adaptive self-oscillating converters is developed for high-efficiency and low-cost LED driving. They consist of BJT-type self-oscillating units, loss-adaptive BJT driving units, and low-loss current sensing units. In this paper, a self-oscillating buck converter, one of the family members, is chosen to be introduced in detail. The contents include the operation principle, a...
Due to the characteristics of high reliability, wide speed scope with high efficiency, and low cost, Switched Reluctance Generator (SRG) system is suitable for applications in the field of variable-speed constant-voltage generation, such as wind power generation, flywheel energy storage, electric vehicle, aircraft power generator, etc. In this paper, a nonlinear dynamic model of SRG system is established,...
This paper proposes a novel single-stage LLC resonant ac-dc converter with power factor correction feature. The proposed circuit is the integration of a buck-boost type power factor corrector and an LLC resonant dc-dc converter. The proposed single-stage converter which has power factor correction and output voltage regulation features can simplify circuit complexity, reduce cost, and increase system...
Over the past decade, the resistive memory device known as RRAM has been studied extensively in many ways, and many of its problems have been identified, discussed, and some solved. It is time to move from material, process, and device to circuit design and yield, in order to commercialize RRAM. However, as we move from resistive device to memory circuit, new problems do appear, partly because the...
An intelligent integral backstepping sliding mode control (IIBSMC) system using a multi-input multi-output (MIMO) recurrent neural network (RNN) is proposed to control the position of a levitated object of a magnetic levitation system considering the uncertainties in this study. First, the dynamic model of the magnetic levitation system is derived. Then, an integral backstepping sliding mode control...
This paper proposes a cascade control strategy, combined of a modified sliding mode controller and a quantized current regulator, for a brushless DC motor (BLDCM) to achieve high-performance speed control. In the current control loop, the quantized control law is derived by minimizing the instantaneous square value of a performance index signal using the theory of variable structure control to perform...
A bidirectional zero-voltage-switching (ZVS) and zero-current-switching (ZCS) full-bridge dc-dc converter is proposed in this paper. The proposed full-bridge converter topology with low ripple input current, which converts the energy from battery to DC bus (or load) and vice versa. In order to improve the overall efficiency, the proposed bidirectional converter uses the leakage inductance of the transformer...
A composite service consists of many Web Services. The execution of a composite service is conducted by an execution engine according to the workflow specification. Since different composite services might share and access some of the Web Services concurrently, ensuring the correctness of the concurrent execution of the composite services becomes an important issue. This paper proposes a concurrency...
A composite service can be built from Web Services. Some of the composite services require transactional properties to ensure their successful execution. Since different composite services might access the same Web Services concurrently, controlling the access to these shared services is an important issue. This paper proposes a static analysis technique for helping concurrency control mechanisms...
A composite service can be built from Web Services, and, its workflow can be specified using BPEL4WS. Many composite services are long-running transactional processes. This paper proposes a concurrency control scheme for executing transactional composite services. The scheme uses the information gathered from the workflow specifications of the composite services to guarantee the correctness of the...
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