共查询到17条相似文献,搜索用时 109 毫秒
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为适应航空电源品质的新需求和发展的快节奏,综合先进的现代EDA技术与脉宽调制技术,精心设计航空逆变电路的调制方案。采纳等效面积正弦波脉宽调制(SPWM)生成法构建控制数学模型,通过数值运算和数字转换,运用硬件描述语言VHDL编写实现设计所需的逻辑功能。以PLD元器件为调制控制电路的硬件,采用Max+PlusⅡ软件在EDA实验开发系统(GW-GK系统)上完成仿真和硬件测试实验,获得了三相SPWM波形脉冲序列,实现了数字化控制,确保了输出波形谐波量小,波形接近理想正弦波形,同时简化了控制电路的结构和规模,提高系统的控制精度及其可靠性。 相似文献
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针对声频定向系统中方波信号谐波过于靠近基波的缺点,以FPGA为控制核心,设计了灵活高速的SPWM(正弦脉宽调制)载波产生系统。根据自然采样法原理计算SPWM信号的脉宽数据,由脉宽控制模块完成SPWM信号输出。通过该方法获得的SPWM信号与早期的载波产生系统得到的方波信号相比谐波分量离基波更远,系统产生的SPWM信号脉宽精度高,工作稳定。 相似文献
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以提高正弦波脉宽调制(SPWM)供电质量为主要目的,SPWM脉宽调制法通常可分为两电平、三电平和多电平调制法,其中,三电平SPWM波比两电平SPWM波有更好的消除谐波特性。并且基于三电平的SPWM规则采样法是一种为简化SPWM波开关点计算衍生出来的计算方法,一定程度上可以替代比较调制算法。本文提出了一种三电平SPWM波开关点实时计算的方法,并且给出一般性计算公式。通过MATLAB编程,对计算结果进行了谐波分析,同时为了与实际应用相结合,提出了一种包含死区时间的三电平SPWM规则采样算法。在设计开关点算法时,把死区时间计算在内,分析了谐波含量,为工程应用作了铺垫。 相似文献
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文章研究了有源电力滤波器的两种谐波电流检测算法,ip-iq法对负载电流中的谐波进行全部检测,基于用户侧谐波和无功补偿的检测法仅对用户自身造成的谐波进行检测。仿真结果表明,通过APF补偿后,前者电源电流为正弦波,后者电源电流和电源电压保持相同的畸变率,波形相似。 相似文献
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本文研究了有源电力滤波器的两种谐波电流检测算法,ip—iq法对负载电流中的谐波进行全部检测,基于用户侧谐波和无功补偿的检测法仅对用户自身造成的谐波进行检测。仿真结果表明,通过APF补偿后,前者电源电流为正弦波,后者电源电流和电源电压保持相同的畸变率,波形相似。 相似文献
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逆变控制技术直接影响三相应急电源(EPS)输出波形的质量和整机效率。文中采SVPWM算法和数字控制技术,与传统SPWM算法相比,提高了EPS输出波形的质量和输出电能的效率;波形控制中采用电压瞬时值内环、平均值外环的双环控制,降低了波形畸变率,使正弦波电压输出更稳定。 相似文献
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Slip energy recovery induction motor drives are used in high power applications, in which by controlling the slip power a variable speed drive system is provided. However, poor power factor is a disadvantage of the system. Presence of sub-harmonics of the line frequency on the stator side is one of the special features of these drives. A phase-controlled inverter can absorb the reactive power from the supply and inject the low-order current harmonics with relatively high amplitudes to the supply. This paper simulates the harmonic content of waveforms in various points of drive at different speeds, based on the hybrid model (dqabc). Then the sinusoidal pulse-width-modulation (SPWM) control technique is used in order to improve the power factor of the drive and to weaken the injected low-order harmonics to the supply. Based on the frequency spectrum, total harmonic distortion, distortion factor and power factor, two phase control and SPWM techniques are compared and the advantage of the SPWM technique over the phase control technique is shown 相似文献
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介绍了PMSM(永磁同步电动机)控制原理,SPWM(正弦脉宽调制)和SVPWM(空间矢量脉宽调制)算法,并建立了基于这两种算法的永磁同步电动机控制系统仿真模型,且对模型运行结果进行了FFT分析。分析结果表明:采用SVPWM算法控制永磁同步电动机定子绕组电流总谐波失真,远远小于采用SPWM建立的模型,在永磁同步电动机数字控制系统中SVPWM是更理想的选择。 相似文献
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基于可变速率采样的SPWM算法设计及实现 总被引:1,自引:0,他引:1
SPWM调制是提高逆变电源电压利用率和减少谐波分量的重要方法。文章依据正弦信号的波形特点,从采样速率转换时刻的确定、采样速率的选择及脉冲换相点的计算等方面详细讨论了可变速率采样的SPWM算法原理和参数选择。最后给出采用STC12C5410AD系列单片机的软、硬件实现。 相似文献
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With the development of motor-driven technology, the pulse width modulation (PWM) method plays a key role in the servo-control system and motor speed control. In recent years, sine PWM (SPWM) becomes the nucleus of a motor speed control system by means of variable voltage and variable frequency (VVVF). However, the harmonic component of the inverter output wave impairs applications in practice. As for applications, harmonic suppression technologies should meet the needs of high voltage a… 相似文献
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A stand-alone, unity power factor, current-regulated sinusoidal pulsewidth modulated (SPWM) rectifier is described. The topology is based on the series connection of three four-valve single-phase bridges, which allows the conventional two-stage logic SPWM strategy to be used without interphase interference. The problems of stability and low harmonic waveform distortion are identified. Solutions are found by using a simple local notch filter feedback circuit that fulfils the dual function of stabilizing and active filtering. From the clarification given by this more expensive but less constrained topology, the stage is set for the next step in incorporating the lessons learned to the more economical topology based on the six-valve, three phase parallel bridge, which requires a tristate logic for PWM control when operating in the current-source configuration 相似文献
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The objective of this paper is to propose two different modified sinusoidal pulse width modulation (SPWM) control schemes, MPWM-S and MPWM-T, for the dc/ac inverter with a non-constant dc voltage source. The amplitude distortion of the pulse width modulated waveforms is caused by the input dc voltage source variation and has the most significant impact on the dc/ac inverter’s ac output voltage spectral errors. The proposed MPWM-S and MPWM-T can achieve the desired fundamental amplitude and eliminate the low order harmonic components caused by the dc voltage source variation. The mathematical analysis of the amplitude distortion and the systematic development of the MPWM-S and MPWM-T are presented in this paper. The proposed MPWM-S and MPWM-T are feed-forward compensation methodologies and can be integrated with any practical feedback control schemes. Hardware implementations of the proposed control schemes can be easily accomplished by adding one or two analog multipliers to the traditional SPWM control circuit. The performance of the two proposed modified SPWM control schemes is verified by experimental results. 相似文献
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采用移相的原理,将无谐波失真的标准信号移相后与被测的失真信号相叠加,同时使标准信号的相位与被测的失真信号中的基波的相位相反,而两者的幅度值相等,结果将基波成份抵消而保留了谐波成份,由此而测出谐波失真度。 相似文献