电流的

In this paper, the change of back electromotive force current with the different PWM modes are analyzed in detail on the base of BLDCM model. According to theory and experiment ,ON-PWM type restrains the peak value of back electromotive force current and brings the lest effect to the motor control system.

基于无刷直流电动机的数学模型，分析比较了不同PWM调制方式下反电势电流的变化规律，并通过理论推导和仿真实验证明了当电机系统采用ON-PWM调制方式时，能有效地抑制反电势电流的峰值且对电机控制系统造成的影响最小。

The results show that the current pulse voltage and frequency on the solidification structure optimization have a best value.

研究了不同参数的脉冲电流对Q235钢凝固组织的影响，结果表明：脉冲电流的电压和频率对凝固组织的优化有一最佳值。

Based on analysis of the features of three-phase four-line power supply system and nonliear load current harmonic pollution,compensation method of simultaneously compensating voltage sag and synthetic power quality of load low-voltage of harmonic current was proposed,and corresonding hybrid unified power quality compensator was also designed.

通过对三相四线制供电系统的特点和非线性负载电流谐波污染分析，提出了可同时补偿电压跌落、谐波电流的负载端低压综合电能质量补偿方法，并设计了对应的混合型低压电能质量综合补偿器。

In the case of short - circuit,the output current amplitude and phase of PWM converter are controlled to adjust the equivalent impedance of current - limiter for fault current suppression.

故障发生后，通过变流器控制变压器二次侧注入电流的相位和幅值，进而调节限流器的等效阻抗，从而实现抑制短路电流的目的。

An effective method for low perming error of fluxgates is to enlarge the peak value of the excitation current, but large amplitude excitation will increase the power consumption.

降低磁通门剩磁误差的有效方法是增大激励电流的峰值，但大的激励电流峰值将增大功耗。

The radio knife is high frequency power equipment based on the theory that electricity concentrates on the skin. It can directly cut the tissue, homeostasis and cauterize. The safety requirement of this equipment is very strict because unsafe operation will burn the tissue, cause temporal unaware hurt and even endanger the patient's life.

高频电刀是利用高频电流的&集肤效应&原理，使高频电流对人体组织直接进行切割、止血或烧灼的一种高频大功率电器设备，故其安全性要求极为严格，一旦出现安全问题，将出现灼伤，还可能造成一些暂时难以觉察的影响，甚至导致生命危险。

According to the characteristics of the conventional rectifier circuit that there exists a dead area with top wave,a new nonlinear rectifier circuit with impedance transformation has been.

针对常规整流电路输入电流存在死区、呈尖顶波的特点，设计了一种非线性阻抗变换整流电路，从而有效地克服和缩小了输入电流的死区范围，同时改善了系统的功率因数品质。

The one-cycle control equation and control circuit in three-phase bridge is similar to the three-phase three-wire system,the control equation and control circuit in N-phase half-bridge is mainly set up through analysis to the circuit.

有源电力滤波器是一种可动态地补偿谐波和无功电流的电力电子装置，四桥臂三相四线制APF可用于三相四线系统的谐波和无功电流的补偿。

The topology of the three-phase three-wire voltage-type active power filter is analyzed. Based on the analysis, a novel control strategy is developed. Its objective is to minimize the composite error of the three-phase source current whose correlation control can be realized at the same time.

在分析三相三线电压型有源滤波器拓扑结构的基础上，提出了三相电流综合误差最小的开关控制策略，实现了三相电流的关联控制。

Two examples of making use of this structure are presented in Chapter 2; one is a study for self-heating effect and the other is a characterization between channel and LDMOS currents.

两个利用此种特殊结构的例子将在第二章中被讨论；一个是对自我加热效应(self-heating effect)的研究，另一个是对通道电流与LDMOS 电流的特性分析。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。