首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 232 毫秒
1.
分析单相PWM整流电路的结构、工作原理和控制方法,通过选择适当的工作模式和工作时序,可使PWM整流电路输出直流电压稳定。将正弦脉宽调制技术应用于PWM整流电路,使其交流侧输入电流非常接近正弦波,且与输入电压同相位。同时调节交流侧电流的大小和相位,使能量在交流侧和直流侧双向流动。在建立基于Simu-link7.6的仿真模型基础上,通过分析PWM整流电路各处电压、电流波形,验证其控制方法及仿真设计的正确性。  相似文献   

2.
提出了一种新型的基于单周期控制的单位功率因数整流器为井下电机车供电。该电源由维也纳整流级和高频隔离DC-DC变换级两级功率变换器级联构成,但控制电路采用一级协调控制。电路控制简单,不需要乘法器和输入电压检测就可以实现单位功率因数运行,且可以降低开关器件一半的电压应力。详细分析了新型整流电路的基本工作原理和双闭环控制策略,并通过仿真和试验对此新型电路拓扑及其相应控制策略的正确性进行了验证。  相似文献   

3.
在传统使用液压作动器的大功率临界飞行应用领域中,由于机电作动器应用的增加,对机电作动器负载系统正确、可测量模型的需要也增加了。火箭发动机的推力矢量控制就是这样的一种应用。这时提出了一个机电作动器推力矢量控制系统的直观的线性化的模型和估计模型参数精确而又实用的方法。估计技术是使用工程设计数据的计算与以设计用于分离单独参数效应/或组合参数效应的第一原则为基础的实验相结合。这些技术使用一些通常在一个机电作动器系统中有用的测量结果和由计算机或信号发生器产生的输入数据。模型的有效性和参数预测技术由火箭发动机的模式模拟器和为推力矢量控制设计的一个机电作动器在实验中证实。本文还讨论了非线性及其模拟问题。由后冲力引起的共振漂移由实验数据来证实。  相似文献   

4.
赵天  杨智春  刘昊  Kassem MOHAMMED  王巍 《航空学报》2018,39(12):222308-222308
压电陶瓷叠层作动器的迟滞蠕变非线性特性严重影响了控制系统的稳定性及动态跟踪精度。针对其迟滞蠕变非线性补偿控制问题,提出了一种高精度动态补偿压电陶瓷叠层作动器非线性特性的自适应混合补偿控制方法,即迟滞蠕变前馈补偿与自适应滤波反馈补偿结合的前馈-反馈混合控制方法。采用改进的Prandtl-Ishlinskii(Modified Prandtl-Ishlinskii,MPI)模型对压电陶瓷叠层作动器迟滞蠕变非线性特性进行精细化建模,并得到其逆补偿模型进行前馈补偿。根据前馈补偿误差,采用自适应滤波反馈控制对输入信号进行实时调控,实现对压电陶瓷叠层作动器的迟滞非线性及lg(t)型蠕变特性的实时精确补偿控制。数值仿真与实验结果表明,相比于常规前馈迟滞蠕变补偿,所提出的自适应混合补偿控制方法可以有效降低压电陶瓷叠层作动器的迟滞补偿误差,极大提高了迟滞蠕变非线性动态跟踪精度以及自适应性。  相似文献   

5.
针对载人月面巡视器电源负载能力受限问题,提出了基于太阳电池阵、蓄电池和超级电容器组成的混合电源技术。通过对现有的空间混合电源系统进行分析,确定了包含直流变换器的共太阳电池阵单母线结构的混合电源系统方案;建立了混合电源关键模块仿真模型,提出了功率分配控制策略,并对巡视器在大功率负载情况下的混合电源状态进行仿真,结果表明混合电源可按照功率分配控制策略调节蓄电池与超级电容器的充放电,达到了预期要求。  相似文献   

6.
提出了一种新型的基于压电陶瓷的非接触式空气作动器,对其静、动态特性进行了分析与实际测 试,并进一步对基于空气作动器的混合隔振系统进行了分析与仿真。  相似文献   

7.
目前机电作动器传动机构存在刚体数目多、传动链长、动力学模型难以建立的问题。通过引入规范化的动力学建模方法——集中质量等效元素法,建立了某机电作动器传动机构的动力学模型,包括等效系统质量阵、等效系统力系和系统自由坐标与广义坐标之间的雅克比关系阵,并得到了其解析动力学方程;结合方程在ADAMS平台进行动力学逆求解仿真,得到了30°大行程位移信号和8Hz频率信号两种工况下的系统载荷响应曲线。随着负载转动惯量增加,电机动载系数达到1.34,丝杠动载系数达到1.55;外部负载不变时,随着驱动信号幅值增加,电机动载最大系数达到1.23。分析表明随着机电作动器系统外部惯性负载及系统运动速度的提高,由外部惯性负载及自身传动机构产生的动载效应明显,为机电作动器传动机构优化设计提供了理论依据。  相似文献   

8.
机载电静液作动系统的发展现状与关键技术研究   总被引:3,自引:0,他引:3  
总结了新型机载作动系统的发展背景与研究意义,介绍了用于功率电传的电静液作动器和机电作动器的发展现状,综述了机载电静液作动系统设计、开发和取得的技术成果,论述了机载电静液作动系统发展中有待于进一步研究的问题,提出了开展该项研究的建议和措施。  相似文献   

9.
为在伺服电机上实现准确的位置调节,提出了基于扩展状态观测器的鲁棒复合伺服控制和带误差积分的线性反馈控制方案,并以闭环阻尼和自然频率等作为设计参数,给出了全参数化的离散时域控制律。控制律在1台永磁同步电机上进行了试验测试。结果表明鲁棒复合控制在较大范围的位置目标和负载转矩下实现准确的点位运动,瞬态性能良好;而基于积分的线性反馈控制当目标位置或负载发生变化时伺服性能出现明显恶化,缺乏鲁棒性。  相似文献   

10.
襟缝翼机电作动器是飞机高升力系统中的关键运动部件,其速度控制对襟缝翼的姿态调节十分重要。然而,襟缝翼机电作动器易受到翼面周期性或非周期性气动载荷干扰,传统的比例积分型速度控制器性能实现受限。为此,本文提出一种基于比例谐振自抗扰控制器(ADRC),在抑制非周期性干扰基础上还可抑制特定次周期性干扰。周期性干扰通过采用比例谐振控制的扩展状态观测器来估计。通过试验,比较了比例积分型控制器、传统线性自抗扰控制器和比例谐振型自抗扰控制器的控制性能,验证了本文所提出的方法可以显著抑制干扰、提高机电作动器的速度控制精度,为飞机平稳起降提供技术支撑。  相似文献   

11.
Novel hybrid 12-pulse line interphase transformer (LIT) rectifier systems with integrated single-switch or two-switch boost-type output stage that ensure a constant output voltage independent of mains and load conditions are proposed for supplying actuators of future more electric aircraft. The principle of operation, the dimensioning, and the system control are discussed. The theoretical considerations are experimentally confirmed for a 10 kW laboratory prototype. Finally, the single-and the two-switch system are comparatively evaluated concerning the level of input current ripple, power factor, and overall efficiency.  相似文献   

12.
在双闭环控制的基础上,分析了整流器的模糊PI控制,建立了三相PWM整流器MATLAB/SIMULINK仿真模型。结果表明,该方法能够实现PWM整流器的高功率因数并且有良好的动态性能,从而验证了所提出方法的可行性和有效性。  相似文献   

13.
Three control techniques for a high power factor multilevel pulsewidth modulation (PWM) rectifier are proposed. The proposed rectifier is based on series connection of full-bridge cell to achieve a high power factor, low current distortion, low voltage stress of power semiconductors and two balanced output voltages. The look-up table is used in the proposed control schemes to reduce the hardware circuit. A capacitor voltage compensator is used to balance two dc capacitor voltages in order to obtain high quality PWM voltage pattern. Based on the proposed control schemes, two-level or three-level PWM pattern can be generated on the ac side of the adopted rectifier. The proposed techniques for a high power factor multilevel rectifier illustrate its validity and effectiveness through the respective simulations and experiments. According to the measured results, the current harmonics drawn from the mains meet the International Electrotechnical Commission (IEC) 1000-3-2 limits  相似文献   

14.
High power factor AC/DC/AC converter with random PWM   总被引:1,自引:0,他引:1  
A three-phase AC/DC/AC converter is presented with a power factor preregulator to improve the power quality in the input side and a pseudorandom noise generator to reduce the emitted acoustic noise and the mechanical vibration for an induction motor drive. The space vector modulation with hysteresis current control for a voltage source rectifier is adopted to simplify the hardware circuit. A control scheme is presented to drive the supply current following the reference current. The amplitude of reference current for the pulsewidth modulation (PWM) rectifier is derived from the DC bus voltage regulator and the estimated output power. Random switching frequency technique for a three-phase PWM inverter system to reduce the annoying tonal noise and resonant vibration from an induction motor is described. By randomly varying the instantaneous PWM switching frequency from one cycle to the next, the frequency distribution of harmonics is spread in a wide frequency range. The major advantage for using such a strategy is the nonrepetitive output spectral characteristic that results in reduction of torque pulsations in motor drive systems. The nearly unity power factor at the three-phase rectifier and the absence of acoustic noise concentrated at the specific tones which is usually present with conventional sinusoidal modulation are verified by the experimental tests  相似文献   

15.
A single-phase ac/ac converter based on neutral-point-clamped scheme is proposed to perform unity input power factor and to provide a stable ac voltage to the critical loads. The ac/dc rectifier part is controlled to generate a unipolar pulsewidth modulation (PWM) waveform on the ac terminal by using four power switches with voltage stress of half the dc-link voltage. The carrier-based current control scheme is employed in the inner control loop to track the line current command. To regulate the dc bus voltage, a proportional-integral (PI) control is adopted in the outer control loop. The dc/ac inverter part of the system with four power switches is employed to generate a stable and clean sinusoidal output voltage to the critical load. The instantaneous current control scheme is used to track the output voltage command. To verify the effectiveness of the proposed control algorithm, the simulation and experimental results based on a laboratory prototype were implemented and discussed.  相似文献   

16.
A novel ac/dc/ac converter topology with three-level pulsewidth modulated (PWM) scheme for the single-phase ac/dc rectifier and random PWM scheme for ac drives is proposed. In order to improve the power quality in the single-phase rectifier, a ROM-based (read-only memory) control scheme, based on hysteresis current comparator, region detector, and capacitor compensator, is used to achieve a sinusoidal line current with low current distortion. The control scheme of the adopted three-level rectifier is easy to implement. The blocking voltage of power switches is clamped to half of the dc bus voltage. To reduce the mechanical vibration from an induction motor, random pulse position PWM scheme is adopted to spread the harmonics in a wide frequency range which results in the reduction of torque pulsation in the ac motor drives. Simulation and experimental results based on the laboratory prototype circuit are presented to verify the proposed control scheme  相似文献   

17.
A single-phase power factor preregulator to improve the power quality in the input side of an ac/dc/ac converter and a random pulsewidth modulation (PWM) to reduce the emitted noise energy and the mechanical vibration for an induction motor drive is proposed. The hysteresis current control (HCC) technique for a voltage source switching mode rectifier (SMR) is adopted. A control scheme is presented such that the line current is driven to follow the reference current which is derived from the dc bus voltage regulator and the output power estimator. A random pulse position technique for a three-phase voltage source inverter system to reduce the noise energy and resonant vibration from ac machine drive is described. By randomly varying the instantaneous pulse position in each switching frequency, the frequency distribution of harmonics is spread in a wide frequency range which results in reduction of torque pulsations in the ac motor drive systems. To investigate the proposed control scheme, experimental tests based on a laboratory prototype were implemented to show the nearly unity power factor at the SMR and reduce the noise energy concentrated at the specific tones  相似文献   

18.
传统开关磁阻电机(SRM)起动时采用电流斩波控制(CCC),中高速阶段采用角度位置控制(APC)对转速进行调节。但在电动车领域的SRM驱动控制中,通常采用基于脉宽调制(PWM)控制的方式来实现电机的开环调速。在传统SRM控制方式的基础上,提出了一种动态斩波的起动方式以及一种PWM控制与APC控制相结合的中高速运行的综合控制策略,可确保电机在不同负载下平稳起动、瞬间提速和稳定运行。与此同时,对控制器保护环节中最为关键的过流保护和堵转保护进行了设计,提升了整个驱动系统的可靠性。为了验证所提驱动控制策略和保护方法的可行性,在以STM32F103处理器为控制核心的控制器和1台12/8结构电动车SRM上进行了系统的试验。试验结果表明在该控制算法下,电机能够快速起动和稳定运行,且能检测到故障并及时保护,证明了该算法的正确性。  相似文献   

19.
The design and implement action of a DSP-based fully digital-controlled single-phase pulsewidth modulated (PWM) dc-ac converter for ac voltage regulation is described. The proposed multiloop digital controller (MDC) consists of a current controller, a voltage controller, and a feedforward controller. This MDC was realized using a single-chip digital signal processor (DSP). The PWM gating signals are determined at every sampling instant by the proposed multiloop digital control scheme using a set of detected feedback signals. A software current control; scheme has been developed to achieve fast current control of the PWM inverter and decouple the inductor of the output filter. Experimental results have been given to verify the proposed digital control scheme. The constructed DSP-based PWM dc-ac converter system can achieve fast dynamic response and with low total harmonic distortion (THD) for rectifier type of loads  相似文献   

20.
李林  吴红飞  朱建鑫  黄家杰  杨帆 《航空学报》2021,42(6):624584-624584
为了消除高峰均功率比低频脉冲负载对有限容量机载交流供电系统的周期性冲击等不利影响,对开关器件进行集成和复用,提出了能够同时提供功率解耦端口和直流输出端口的三端口功率解耦整流器。通过将三端口整流器与DC/DC变换器组合,构造出集成低频脉冲功率解耦端口的机载电源系统,实现了直流侧周期性脉动功率和交流源侧功率的解耦,并保证低频脉冲负载正常供电需求。详细分析了三端口整流器的工作原理,提出了与之相适应的功率控制方法和调制策略,基于开关器件分时复用原理,实现了交流端口到两个直流端口的功率传输和分配,并实现了两个直流端口功率切换过程的平滑过渡。实验结果验证了所提三端口脉冲功率解耦整流器的有效性和可行性。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号