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A voltage regulator circuit for low power flash memories is presented. The voltage regulator circuit was implemented in a flash chip realized with a 0.18 um flash technology. Experimental results show that standby current is less than 0.3 μA at 1.8 V and 25 °C.

The DC bus voltage is the main criteria to reflect whether the converter system is working properly or not, and the stability control of the DC bus voltage is the key to ensure that wind power generators not take off the grid when grid voltage drops. This paper had done research on a direct-drive wind power system and proposed a coordinated control method based on the grid voltage information feedforward with a crowbar circuit. The hardware was combined with the improved control strategy in this method. When the grid voltage drops, the extra energy of the DC bus can be unleashed by the crowbar circuit, at the same time, the output power of motor-side can be controlled according to the grid-side information, and the mechanical speed of motor-side can be suppressed by the pitch angle regulation when the output power reduces. Thus, the DC-bus voltage can be keep stability. Results based on Matlab/Simulink simulation shows that this method not only improves the stability and dynamic response performance of the DC bus voltage, but also effectively maintains the output power of generator and reduces the action time of crowbar circuit. The ability of the wind power system riding through the grid fault has been effectively improved.

The high voltage circuit breaker is an important power system equipment. The reliability of its running relationship with the safe operation of the entire power system. High voltage circuit breaker on-line monitoring system enables real-time monitoring of various parameters during the operation in which the circuit breaker, and the use of communication to achieve data transfer bus information. Through monitoring points, closing coil current signals to constitute the core of C8051F online monitoring unit via RS-485 serial bus will monitor information is uploaded to the master computer.

This paper presents an intelligent method of optimized control of DC voltage based on BP Neural network, on account of this presentd method, by collecting parameters of grid voltage and significant frequency of harmonic current, then, construct couples of tranining samples and fully use the advantages of BP Neural network that can discretionarily utlize arbitrary precision to approximate any continuous function, and computing the optimized voltage of DC side, as a result, achieving online adjustment of capcitors voltage at DC side. Futher more, adjusting the hysteresis width automatically according to the voltage variation of capacitor, thus the voltage of DC side can automatically adapt to fluctuation of grid voltage and load current, so that to obtain comprehensive optimum of power loss and compensation performance of power active filter.

This paper mainly presents the DSTATCOM (Distribution Static Compensator) and its control methodology of DC capacitor voltage. Generally, the dc capacitor voltage is regulated using a PI controller where various control algorithms are used for load compensation. Whenever there is a change in load there is considerable variation in dc capacitor voltage which might affect compensation. In this work, a supervisory method is proposed to reduce the dc link rating. The reduction in dc link voltage leads to the reduction in switching frequency and hence switching losses A considerable reduction in the in dc link capacitor voltage is obtained without compromising the compensating capability. The major power quality issues discussed in this work are harmonics and power factor reduction. The performance of the proposed strategy is proved using the detailed MATLAB simulation studies.

The stability of the high voltage arm resistors has a strong influence on the performance of the resistance high DC voltage divider. So by analyzing the main parameters that affect the resistor value change, including voltage coefficient, power coefficient and so on, a new matching method is proposed to make a high precision high DC voltage divider in this paper. Based on the principle of pairing the resistors and adjusting the big and small ones, a high precision high DC voltage divider could be made with the voltage variation less than 0.005%, even on the condition of using high voltage coefficient and power coefficient resistors.

Power battery in the HEV normally has a high capacity. Therefore during the start-up procedure of HEV motor, pre-charge phase is essential in order to reduce the impact of high current. In this paper, we build a HEV motor pre-charge model then deploy it on cRIO embedded control system to simulate the whole process with high real time. Finally the paper tests some typical fault conditions which demonstrate great benefits.