A novel progressive trigger (PT) method of di/dt control for MOSFET is presented in this paper. The principle of the proposed method is based on the progressive trigger current during ON and OFF states by variable channel width for MOSFET. The experimental results show that the di/dt reduces from 105 mA/nS to 57 mA/nS for OFF state, and from 110 mA/nS to 86.7 mA/nS for ON state with RON = 0.5 Ω and Vgg = 3 V. The flexibility of the method is easy to implement in integrated circuits.
This paper presents a high reliability high voltage driver integrated circuit (IC), which has been designed and fabricated for half bridge inverter drive of the intelligent power module (IPM). By utilizing the 1.0 µm 650 V high voltage bipolar CMOS DMOS (BCD) on silicon-on-insulator (SOI) process technology combined with modified level shift circuit, the proposed high voltage driver IC offers an improved immunity to di/dt induced substrate noise, with a negative voltage undershoot down to −50 V which is about 1.5 times of the maximum allowable value of the conventional high voltage driver ICs at 100 °C, thus delivers higher reliability. Furthermore, this device also needs ultra-low quiescent supply currents and offers high driver capability (source 200 mA, sink 300 mA). In addition, this device can operate at a high temperature up to 175 °C and features higher breakdown voltage and lower leakage current than conventional high voltage driver ICs.
This paper builds up an accurate nonlinear mathematical model of an electro hydraulic force/torque servo control system, and provides a thorough theoretical analysis on the feedforward compensation for extraneous force/torque, whose limitation is analyzed and revealed. The nonlinear factors and the servo valve dynamics have much influence on the system characteristics. Subsequently a velocity synchronizing compensation method by using the control signal of the control actuator is proposed, which can reduce the lagging effects for the better performance. For the reason of similarity between the model of control actuator and that of the load simulator, the proposed method performs well against the influence of nonlinear factors. The simulations and the experiments confirm that this control scheme results in a quick response, robustness, and excellent ability against disturbance.
A reliability improved synchronous boost converter with spike suppression circuit is proposed in this paper. Compared with the traditional boost converter, a novel control circuit is designed to suppress the voltage spike at node SW during the dead time. In addition, the two main power switches could be avoided to operate in ON state during the transient process. Hence, both the reliability and the efficiency are improved. The converters with/without spike suppression circuit are designed and implemented in a 0.5 µm standard CMOS processes. The experimental results show that the voltage spike at node SW is reduced 43% when the load current is 0.5 A, and the efficiency is improved at light load.
Elimination effect of different Cl-concentration to Ammonia Nitrogen determination was investigated through experiments.The results showed that Clcould effect the determination of Ammonia Nitrogen in the different range,and elinmination method was comparable with distillation.
Abstract In the analysis of liquid-filled piping systems there are Poisson-coupled axial stress waves in the pipe and liquid column, which are caused by the dilation of the pipe. In some conditions the influence of viscous friction that is usually frequency-dependent should not be omitted, which in fact is another kind of coupled form. It directly influences the amplitude of vibration of piping systems to some degree. The larger the viscosity of the liquid is, the greater the influence will be. Budny (1991) included the viscous friction influence in time domain analysis of fluid-structure interaction, but did not give frequency domain analysis. Lesmez (1990) gave the model analysis liquid-filled piping systems without considering friction. If the friction is not included in frequency domain analysis, the vibration amplitude will be greater than that when friction is included, especially at harmony points, cause large errors in the simulation of fluid pipe network analysis, although it may have little influence on the frequency of harmony points. The present paper will give detail solutions to the transfer matrix that represents the motion of single pipe section, which is the basis of complex fluid-structure interaction analysis. Combined with point matrices that describe specified boundary conditions, overall transfer matrix for a piping system can be assembled. Corresponding state vectors can then be evaluated to predict the piping and liquid motion. At last, a twice-coordinate transformation method is adopted in joint coupling. Consequently, the vibration analysis of spatial liquid-filled piping systems can be carried out. It is proved to be succinct, valid and versatile. This method can be extended to the simulation of the curved spatial pipeline systems.
This paper presents a SiC intelligent power module (IPM) which features low power loss. It is designed specifically for high performance low power motor drive applications including fans, refrigerator and air conditioner compressor drives, where energy efficiency is a major concern. The IPM utilizes 600 V planar-type SiC metal oxide semiconductor field effect transistors (MOSFETs) as the power switching devices to deliver immensely low conduction and switching losses. Moreover, 600 V SiC schottky barrier diodes (SBDs) are adopted as the freewheeling diodes. In comparison with conventional silicon fast recovery diodes (FRDs), SiC SBDs exhibit practically no reverse recovery loss and can further diminish the power loss of the IPM. Besides, combined with these SiC power devices the proposed IPM is able to operate at a higher temperature up to 175°C while maintaining very low leakage current. Experimental results indicate that the power loss of the proposed IPM is between 2.2∼17 W at different compressor frequencies from 10 to 70 Hz, which can realize up to 32%∼53% improvement when compared to state-of-the-art conventional Si-based insulated gate bipolar transistor (IGBT) IPM.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)