共查询到19条相似文献,搜索用时 296 毫秒
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吴晓峰 《航空精密制造技术》1983,(4)
带隙式基准源的输出等于硅材料的能隙电压,它具有抛物线温度特性,调整电阻可使温度系数为零。它解决了齐纳二极管难解决的问题:输出低的基准值、长期稳定性和热稳定性,是高精度D/A转换器的理想基准源。 相似文献
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设计功率MOSFET驱动电路时需重点考虑寄生参数对电路的影响。米勒电容作为MOSFET器件的一项重要参数,在驱动电路的设计时需要重点关注。重点观察了MOSFET的开通和关断过程中栅极电压、漏源极电压和漏源极电流的变化过程,并分析了米勒电容、寄生电感等寄生参数对漏源极电压和漏源极电流的影响。分析了栅极电压在米勒平台附近产生振荡的原因,并提出了抑制措施,对功率MOSFET的驱动设计具有一定的指导意义。 相似文献
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针对半球谐振陀螺受温度影响出现零位漂移的问题,以测温电路温度为基准,建立温度频率函数实时解算温度,提出一种基于粒子群优化(PSO)算法的半球谐振陀螺惯导系统陀螺温度补偿方法。在求解温度时,需要先将温度频率函数转换为一元三次方程,存在测试计算量大的问题。引入逆向拟合思想,建立频率温度函数,提高陀螺输出温度实时性和降低测试计算量,替代了传统陀螺测温硬件电路,为惯导系统轻小型设计提供新思路。考虑温度变化、温度变化率以及两者的交叉项,建立温度补偿模型,引入PSO算法求解模型系数。温度试验结果表明,在温箱温度为-40~50 ℃内,补偿后的半球谐振陀螺的零偏稳定性较补偿前提升了46%。 相似文献
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温度变化引起的静压液浮陀螺漂移的补偿研究 总被引:2,自引:0,他引:2
本文就温度变化引起的陀螺漂移的补偿展开分析,提出了用大力矩器线圈闭合力反馈回路,中力矩器线圈外加补偿电流来补偿由温度变化引起的陀螺漂移的方法;并对据此设计的实验数据采集系统及补偿电路予以了分析,通过实验验证了补偿原理的可行性。 相似文献
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伺服驱动器由于具有很强的非线性,导致永磁同步电机(PMSM)的定子电流中含有大量的高次谐波并且引发较大的转矩脉动。针对这一问题,提出基于级联型二阶广义积分器(SOGI)的谐波抑制方法,将级联型SOGI与电流环d、q轴的PI控制器并联,利用级联型SOGI提取d、q轴电流中的6次谐波分量,并将其注入到PI控制器的输出电压中,从而抵消参考电压中的谐波。仿真结果表明:采用基于级联型SOGI的电压补偿法进行谐波抑制,电流波形的畸变得到了明显改善,证明了所提算法的有效性。 相似文献
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Analysis and design of a novel three-phase active power filter 总被引:4,自引:0,他引:4
《IEEE transactions on aerospace and electronic systems》2001,37(3):824-831
A novel three-phase active power filter is analyzed and designed. A low cost power circuit configuration of the active power filter is proposed, along with a fast peak detector for synthetic sinusoidal generation technique, in order to achieve almost real time compensating current calculation. This technique avoids the use of mains voltage signal in the calculation of reference compensation current. Therefore, the mains current, after compensation, is still a pure sinusoidal waveform, irrespective of the distortion in the mains voltage. Furthermore, a critical value for the magnitude of capacitor voltage on the dc side, and a critical value for the reactor inductance on the ac side have also been derived, for the successful harmonic current tracking in various design applications. Finally, the performance of the active power filter is demonstrated by simulations as well as experimental results 相似文献
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To avoid the numerical complexities of the battery discharge law of electric-powered rotorcrafts,this study uses the Kriging method to model the discharge characteristics of Li-Po batteries under standard conditions.A linear current compensation term and an ambient temperature compensation term based on radial basis functions are then applied to the trained Kriging model,leading to the complete discharged capacity-terminal voltage model.Using an orthogonal experimental design and a sequential method,the coefficients of the current and ambient temperature compensation terms are determined through robust optimization.An endurance calculation model for electric-powered rotorcrafts is then established,based on the battery discharge model,through numerical integration.Laboratory tests show that the maximum relative error of the proposed discharged capacity-terminal voltage model at detection points is 0.0086,and that of the rotorcraft endurance calculation model is 0.0195,thus verifying their accuracy.A flight test further demonstrates the applicability of the proposed endurance model to general electric-powered rotorcrafts. 相似文献
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IGBT死区效应的存在使三相并网逆变器输出电流不能准确跟踪参考电流,导致系统控制性能较差,而传统的死区补偿方法在相电流过零时存在电流极性判断不准确的问题。针对以上问题,提出一种基于模糊自适应PI策略的三相并网逆变器死区补偿方法。该方案将扰动观测器应用到电流双环模糊自适应PI控制系统中,将死区效应引起的电压误差视为外部扰动,经过扰动观测器估算后,反馈到输入端用以抵消死区效应的影响。模糊自适应PI电流双环控制策略可以解决实际系统响应速度慢、动态特性差的问题。通过MATLAB/Simulink仿真和试验验证了所提方案能够有效降低死区效应的影响,提高系统动态响应。 相似文献
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Current and projected system requirements for inertial reference assemblies emphasize high accuracy, long life, and low power. An inertial reference assembly ( IRA) which embodies the aforementioned characteristics was developed recently. Pulse rebalanced gas-bearing gyroscopes were used to attain high accuracy and long life. Temperature compensation of gyroscope parameters (in lieu of temperature control) and dual voltage spinmotor operation helped achieve low-power operation. The latter two items represent an advancement in the state of the art and form the subject of this paper. These techniques were used in the construction of a three-axis IRA with an operating power less than 50 watts. It has achieved 0.1 percent scale factor accuracy over a 60°F range. 相似文献
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双馈异步发电机(DFIG)在大规模风电并网环境下提供的无功功率无法满足并网需求。虽然引入固定电容器能够提供无功补偿,但系统受功率耦合的影响无法有效实时维持电压稳定。提出了一种静止无功发生器(SVG)与DFIG协调补偿无功的控制策略,同时引入电力系统稳定器(PSS)抑制系统的低频振荡,充分利用DFIG风电机组自身发出无功的能力,减少了SVG的配置容量。在MATLAB/Simulink软件仿真平台建立DFIG风电机组并网模型,仿真结果证实了此控制策略能够完成连续无功补偿,有效维持并网点电压稳定,增强系统输电能力。 相似文献