总谐波

有源功率因数校正（ActivePowerFactorCorrection，APFC）技术的优点是总谐波含量小，功率因数高。

Active power factor correction ( APFC ) technology can achieve high power factor and low total harmonic distortion ( THD ) .

方波型逆变器总谐波失真度（THD）与其负载Q值的关系

Relations between total harmonic distortion ( THD ) and load quality ( Q ) in square wave VSIs

分析了这种电压源逆变器的主要参数，如总谐波失真度（THD）和失真指数（DF）。

The major parameters such as THD and DF of this VSI are analyzed .

其主要优点是：装置可得到较高的功率因数；总谐波畸变（THD）值低；

The advantage of the equipment is that the high PF and low THD can be obtained .

逆变器控制采用优化的特定消谐PWM技术，以滤波后总谐波含量（THD）为目标函数，计算预定开关角度。

The inverter uses optimal selective harmonic elimination PWM technology and computes predetermined switching angle , using total harmonic distortion factor as aim function .

xDSL调制解调器变压器总谐波失真的影响因素分析

Analysis of Factors Affecting Total Harmonic Distortion of Modem Transformer for xDSL Telecommunication

内部的功率因数校正（PFC）电路以临界导通模式（CCM）工作，可获得高功率因数、低总谐波失真（THD）及直流电压调整。

PFC circuitry operates in critical conduction mode ( CCM ) and provides for high PF , low THD and DC bus regulation .

运用了数字信号处理技术，可以得到测试非线性器件总谐波失真（THD）的方法。

Using the digital signal techniques , we can get the model of total harmonic distortion ( i.e. THD ) of the nonlinearity device .

由于前置了功率因数调整器，使系统的功率因数和总谐波失真表现良好，而基于原边控制的控制器能够精确的控制LED电流，并且省去了光耦和二次测控电路，有效的减小了体积。

The power factor correction makes the system power factor and total harmonic distortion performance well . Controller can precisely control the LED current upon primary side regulated ( PSR ) . It spare optocoupler and secondary side regulated control circuit .

电弧炉正常工作时产生大量高次谐波，APF即利用可控的功率半导体器件向电网注入与谐波源电流幅值相等、相位相反的电流，使电源的总谐波电流为零，达到实时补偿谐波电流的目的。

A large number of EAF generated high-order harmonic , APF inject to grid with amplitude equal and the opposite phase current harmonic the power with controllable power semiconductor devices .

有源PFC技术具有功率因数高和总谐波含量小等优点，在过去的二十年里，得到了长足的发展和广泛应用。

Active PFC techniques have been researched systematically and used widely in the recent twenty years because of high power factor ( PF ) and low total harmonic distortion ( THD ) .

总之，逆变器交流输出电压和频率稳定精度均较高，电压波形的总谐波含量THD较低且正弦特性较好。

In short , the inverter AC output voltage and frequency stability precision are higher , and total harmonic content THD of voltage waveform is lower and sinusoidal characteristics are better .

对于方波型逆变器，总谐波失真度（THD）不仅仅随占空比变化，而且受负载类型的影响。

In square wave voltage source inverter , total harmonic distortion ( THD ) is not only the function of duty cycle , but also with response to load 's type .

正弦脉宽调制（SPWM）和空间矢量脉宽调制（SVPWM）由于具有总谐波失真度（THD）小、开关频率恒定、实现方便等优点而在传统逆变器中得到了最为广泛的应用。

Sinusoidal pulse width modulation ( SPWM ) and space vector pulse width modulation ( SVPWM ) techniques are widely used in traditional inverters for low THD , constant switching frequency , convenient realizations etc.

在整周期采样的FFT算法的基础上，提出了确定基波周期的总谐波畸变（THD）最小的方法，并作了误差分析。

Based on the integer period sample FFT algorithm , a lowest total harmonic distortion ( THD ) method for determining the base period is proposed in this paper , and the derivation is theoretically given .

在SPEC-4实际上有较低的总谐波失真低于其更昂贵的兄弟互调失真。

The SPEC-4 actually had lower total harmonic distortion and lower intermodulation distortion than its more expensive brother .

有源PFC可以得到较高的功率因数，总谐波失真（THD）小，可以在较大电压范围内工作，已经成为提高电源功率因数的最主要方法。

However , APFC is a dominating method of improving the power factor , for APFC , within the vast voltage range , can gain the higher power factor and less Total Harmonic Distortion ( THD ) .

经实验验证，输入电流总谐波畸变率在5%左右，功率因数在0.95以上，LLC串联谐振变换器无需外加元件即可实现全程软开关。

The power correction effect can be approved when receive the THD about 5 % , PFC above 0.95 in the input current , LLC series resonant converter can achieve ZVS without any other devices .

其次，本文建立了以输出电压和电流总谐波畸变率为目标的评价函数，并在Matlab/Simulink中搭建了基于PSO算法的三电平和五电平逆变器谐波抑制模型。

Second , this paper determines the evaluation function , which the target is the total harmonic distortion rate of the output voltage and current , and builts the three-level and five-level inverter models in Matlab / Simulink based on the PSO algorithm .

在1kVA的样机上进行实验研究，其结果在额定阻性负载下的稳态总谐波畸变率（THD）为2.49%，空载与额定负载间阶越变化下的电压调整率为6.75%。

The total harmonics distortion ( THD ) for a 1 KVA prototype at rated resistor load is 2.49 % with the voltage regulation for a step change from null load to rated load of 6.75 % .

仿真结果表明，系统输入电流的总谐波畸变率（THD）仅为4.11%，功率因数可达0.999。

Simulation are presented at last , they prove that with the proposed three-phase PFC controller rectifier 's input current total harmonic distortion is only 4.11 % and its power factor ( PF ) can reach 0.999 .

仿真试验分析了弧焊逆变电源工作过程及其动态特性，接于配电网的邻近用户的电压、电流及其THD（总谐波歧变率），弧焊逆变电源输入电压、电流的THD及频谱分析。

The working process , dynamic character , input voltage , input current and their THD of welding inverter were analysed through simulation , so as to current , voltage and their THD and spectrum of neighbor User .

通过简化分析计算表明，牵引变电所采用220kV进线将使电压总谐波畸变率、三相电压不平衡度和电压波动降低。

By simplified analyses , it is revealed that supplying traction substation by 220 kV feed lines can decrease total harmonic distortion , degree of unbalance and fluctuation of voltage .

仿真结果表明，采用MZSVI补偿方法后提高了输出电压，输出电压总谐波含量THD也大大减小。

It is shown by simulation results that output voltage can be increased and the THD of output voltages can also be greatly reduced due to the MZSVI compensation technique .

实验结果表明，该逆变电源控制系统设计合理，在电梯能量回馈系统中采用SVPWM技术，既能提高能量回馈逆变电路对直流电压的利用率，又能减少逆变电能总谐波失真。

Experimental results show that the inverter control system is designed reasonably . SVPWM technique which is adopted in the elevator with energy feedback system can raise the energy utilization of the DC voltage for inverter circuit feedback , and reducing the total harmonic distortion of the inverter power .

基于总谐波畸变最小原则确定基波周期的新方法

A New Method for Determining the Base Period Based on the Lowest THD

结果显示总谐波失真小于9%。

Total harmonic distortion below 9 % is obtained .

数字录放音系统的总谐波失真与动态范围及测量

Total Harmonic Distortion and Dynamic Range of Digital Recording System and their Measurement

二极管支路短路时，负载电压总谐波畸变率相当严重。

The total distorted rate of the harmonics is serious with short-circuit of one of diodes .

单元串联的电路结构使得输出电压总谐波畸变小，对电动机的危害小；

That the circuit structure in unit series makes harmonic distortion little , motor damage small ;