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In order to further understanding of the development and maturation of the renal tubular reabsorption and glomerular permeability functions for the determination of the clinical pathological manifestation and treatment processing of renal diseases, random urine samples were collected from healthy subjects aged from birth to 60 years. All the samples were stored frozen at -70 degrees C for 4 months. The concentrations of the retinol-binding protein (RBP) and microalbumin (MALB) in urine were measured by enzyme-linked immunosorbent assay and at 492 nm with the microplate reader as a valuable marker of renal tubular and glomerular development and maturation The concentrations of RBP and MALB in urine gradually decrease with age. The level of RBP in urine is higher in children before 3 years than after 3 years (P0.01). The levels of MALB in urine is higher in children before 1 year of age than after 1 year (P0.01). Our results suggest that the development and maturation of the glomerular permeability functions and the renal tubular reabsorption are gradual and continuous processes from birth to adolescence but the key stage of their maturation may be at about 1 year and 3 years respectively: and that the rate of the tubular development may be slower than that of the glomerular development. Our results also extend existing data for normal ranges of RBP and MALB in urine from neonates to adults.

This paper analyses the problem of short-term scheduling of the step power plants. In the paper, optimized short-term scheduling models which take the water balance, the energy balance, the delay of water (hydraulic network), the physical properties of hydroelectric station and the capacity of reservoir into consideration is proposed. Also, the application scope and the extension method for the proposed models are presented.

An improved nonlinear control strategy is proposed in this paper. The main improvement made by the authors to the traditional nonlinear control which is based on the differential geometric theory is that an appropriate output function is selected to introduce a nonlinear transformation. Although, such transformation can only partially linearize the nonlinear system, it does provide a way to realize a multi-index control for high order nonlinear systems. Furthermore, with appropriate treatments for the remained part of the nonlinear system after partial linearization, satisfactory performance of the controller can be obtained. The proposed nonlinear control scheme was used to design a coordinated control for a TCSC and a hydro-turbine generator including the excitation and the governor. As the controlled system is a high order nonlinear system characterized with a non-minimum phase problem, design a coordinated control for such system is quite difficult by the conventional nonlinear control theory. Simulation results show very encouraging result. Both dynamic characteristics and the control accuracy of the controlled system are considerably improved.

The multi-functional flexible power conditioner (FPC), which can be considered as a doubly-fed induction machine (DFIM) with a flywheel, is a new kind of Flexible AC Transmission Systems (FACTS) equipment. It can regulate active power rapidly to enhance power system stability and forestall many power system faults. For the special needs of the start process of FPC, a novel direct-start control strategy, which includes some treatments to the speed control system of the rotor-side of back-to-back converters, is proposed in this paper. Detailed analysis of this strategy and experimental result show that it can effectively avoid the start impulsion to the equipment and power system and restraint the power flowed between them.

The multi-functional flexible power conditioner (FPC) can perform multi-functions including energy storage, active and reactive power generation, and considerably enhance power system stability and quality. The motor adopted in FPC is doubly-fed induction machine (DFIM) with large rotating inertia. This paper firstly establishes the model of FPC DFIM. It proposes and analyses the five operation states such as energy storage, active power generation and reactive power generation, speed limitation and floating charge. It puts forward the excitation control strategy of the FPC DFIM with the combination of the power-mode control and speed-mode control. The FPC multi-functions are realized on an asynchronous motor of small capacity. The experimental results verify the excitation control strategy proposed and the good dynamic and static performance of the system while switching control mode under various operation states.

This paper introduces the test equipment working principle of the unified power flow controller (UPFC) and states the feedback variables' choosing for the traditional PI controller of UPFC, then, presents the corresponding control block diagram. After these, this paper proposals a new UPFC control algorithm based on a single nerve cell-adaptive PID control theory, and also presents the corresponding control block diagram; using the digital signal processors implements the hardware platform for UPFC controller in laboratory. In order to compare the control effects using single nerve cell-adaptive PID controller and using traditional PI controller respectively, the three-phase grounding fault and transmission power oscillation simulations are made

Due to its ideal electrical behavior, the superconducting fault current limiter (SFCL) has become one of the most important development trends of limiters in power systems. This paper summarizes the main electrical behaviors of SFCL, including the relationship between SFCL's working current and the quench current of the superconducting coil (SC), and the relationship between equivalent fundamental frequency impedance of SFCL and normal state resistance of SC. Operation losses and response time of SFCL are also discussed. The paper analyzes different influences of quench type SFCL and nonquench type SFCL on waveforms and total harmonic distortion (THD) of line current and node measurement impedance. Electromagnetic simulation is adopted to analyze the characteristics of the SFCL.

HVDC power transmission system is a typical time varying system with many nonlinear relationships among different variables, it is difficult for the conventional PI controller to work effectively for large changes in the operation. In this paper, the synergetic control theory is discussed, and a nonlinear controller based on such theory is proposed for the HVDC power transmission system, in which a constant DC current controller for the rectifier and a constant extinction angle controller for the inverter are designed respectively. Details of design for such control scheme are also given in the paper. In order to verify the effectiveness of the proposed control, the performance the proposed control scheme in the CIGRE benchmark DC transmission system is simulated with PSCAD/EMTDC. The simulation results show that the proposed control works effectively in the start-up process as well as in the conditions when the operation mode shifts for the HVDC system.