基于DSP的三相PWM整流PI调节器设计

通过分析三相脉宽调制（PWM）整流器在a-b-c及d-q旋转坐标系下的数学模型,设计了具有前馈解耦控制的PWM整流器双闭环控制系统。根据系统对电流内环及电压外环的控制要求设计了电流比例积分（PI）调节器及电压PI调节器。最后对整个PWM整流器双闭环控制系统进行仿真,并采用以DSP为核心构建PWM整流器控制系统,仿真和实验结果验证了PI调节器设计的正确性。     

VSC-HVDC抑制并网PCC点电压波动浅析

大型风电场接入电网可能引起电压闪变和波动、电压暂降、电压偏差以及谐波等电能质量问题。通常对风电场进行无功补偿可以抑制系统电压波动,而轻型直流输电则可以起到无功补偿的作用,抑制并网PCC点电压波动、改善风电场的并网性能。     

高压电机综合保护装置的研究

随着科学技术的进步、电力工业的迅速发展,生产系统中的电机数量和单机容量不断增加,相应的电机保护技术也需要有进一步的提高。文中针对电机的各种故障类型,借鉴国内外电机保护装置的经验,并结合现有的高压电机保护技术,提出了一套完整的电机保护方案。这套保护装置包括了低电压保护、过电流保护、差动保护和单相接地保护,可以同时对电机的多种问题实现保护,能有效保障高压电机的正常运行。     

数字控制通讯电源高压防护研究

介绍了一种数字控制通讯电源高压防护电路及其控制方法。数字信号控制器通过检测交流输入电压和PFC输出电压状况做出智能判断,控制高压防护电路中主继电器和辅助继电器的断开和吸合状态,从而对实现通讯电源快速有效的高压防护,提高了通信电源的可靠性。     

低电压高效率微波功率放大器研究与设计

介绍了一种应用于低电压的微波双极性晶体管放大器的电路设计方法。通过分析微波晶体管的模型,比较了小信号法、负载牵引法和文中使用匹配方法对输出功率、效率和线性度的影响。文中设计了一款可以用于GSM通信终端发射的功率放大器,并对采用3种不同匹配方式进行对比,仿真结果表明,文中所用方法输出功率和效率较高、线性度较好。     

Resistorless dual-mode quadrature sinusoidal oscillator using a single active building block

This paper presents a new realization of resistorless mixed-mode (i.e. both voltage-mode and current-mode) quadrature sinusoidal oscillator using a new active building block (ABB) called the differential voltage current-controlled conveyor transconductance amplifier (DVCCCTA). The proposed oscillator circuit uses a single DVCCCTA, two grounded capacitors (GCs) and does not employ any external linear resistors. The tuning laws for the condition of oscillation (CO) and the frequency of oscillation (FO) are non-interactive; and controlled by separate bias currents. The circuit provides two explicit quadrature current outputs and two quadrature voltage outputs and thus can be classified as a mixed-mode quadrature oscillator. Another notable feature of the proposed circuit is that it can also be used as a biquadratic filter to realize low-pass and band-pass filtering functions simultaneously. Non-ideal analysis of the circuit is provided and PSpice simulation results have been included to verify the workability of the proposed circuit.     

A 1 V CMOS programmable accurate charge pump with wide output voltage range

A 1 V, programmable, accurate, high speed, single-ended charge pump is proposed, suitable for low voltage PLLs. It is designed in TSMC 90-nm digital CMOS process and it consists of four switches in a current steering configuration, a unity gain rail to rail buffer for the charge sharing effect elimination, one more rail to rail amplifier for minimizing the DC current mismatch, a programmable current bias circuitry and two drivers based on the standard cell XOR gates specific configuration for achieving good synchronization between all charge pump input pulses at the PLL lock state. Replica biasing technique is applied to all charge pump switches. Current glitches and charge mismatch are suppressed by employing a mechanism with additional switches at the output. It exhibits a maximum DC current mismatch of 1% and charge mismatch of 6% over a wide output voltage range of 0.7 V for the entire range of output currents. The wide range of the output voltage remains relatively constant and independent of the selected charge pump current amplitude. This is attained by applying appropriate variation of the W/L ratios of the bias cascode current sources via the employment of additional programmable switches such that their saturation voltages remain relatively constant, something which in turn enables the output currents range to be as wide as it is required.     

一种最小电压应力的软开关无桥PFC技术研究

针对传统桥式整流升压功率因数校正(PFC)电路效率较低的缺点,提出了一种最小电压应力的软开关无桥PFC电路拓扑.在理论分析和仿真验证的基础上,研制了一台300 W的实验样机.结果表明,改进的无桥PFC电路拓扑具有通态损耗低、电流采样简单,能实现开关管零电压关断和零电流开通,同时实现整流二极管零电压导通和接近零电流软关断...     

AMOLED像素电路的设计与仿真研究

为了解决驱动管阈值电压漂移带来的OLED亮度不均匀的问题,介绍了一种新的AMOLED四管像素电路,利用HSPICE仿真软件详细分析了电路各参数对其输出特性的影响,同时给出了参数设计的方法.最后从延长OLED的使用寿命出发,对电路进行了改进并根据已设计的参数进行了仿真,结果表明改进后的电路功能不变,且在驱动阶段,驱动电流...     

ChargingE-perm for radon measurements

Recharging of commercial E-perm electret detectors used for radon measurement has been investigated. The E-perm was recharged using the poling charging method where a high voltage is applied on a metal nozzle to polarize the electret material. The optimum parameters to recharge the electrets were 5 kV charging voltage and 7 mm height of the nozzle from the electret surface and using an insulator while charging. Under these conditions, charging of E-perm carried out for 15 s attained required voltage and retained the charge for long durations. The response of recharged E-perm for radon activity measurements in a radon calibration chamber and in an open environment was compared with that of CR-39 detectors. Results showed close proximity in radon values.