主电流

Current differential protection is one of the first choices for main protection of EHV transmission lines,so it is worth to research to improve the reliability and sensitivity of line current differential protection.

华中科技大学电气与电子工程学院，湖北省武汉市 430074电流差动保护是超高压线路主保护的首选之一，提高线路电流差动保护的可靠性和灵敏性是一个值得研究的问题。

The high-power system including main circuit, the charging and discharging circuit of synthetic circuit test system, and the principle of charging and discharging for current supply using electrolytic capacitor is presented. At the aspect of circuit breaker control, the advanced permanent magnetic actuator is used and analyzed in this paper, including the precision computation and using in synthetic circuit. The trigger circuit of voltage supply is designed, and the intelligent control is used to trigger the igniting gap. And the integraph based Rogowski coil is designed and employed the intelligent detection of breaking current.

强电系统介绍了合成回路试验系统的主电路及其充放电电路，讲述了电流源采用电解电容器的充放电原理；断路器控制方面，采用当前比较先进的永磁操动机构，并对永磁机构的原理、精度计算和在合成回路中的应用做了详细地分析；设计并制作了电压源点火回路，对球隙点火进行智能控制；在智能检测开断电流方面，设计并制作了与Rogowski线圈相配合的积分器。

The invention discloses a DC/DC circuit, comprising a PWM controller, a current amplifier, a peak current comparator, an error amplifier, a main switch, a synchronous switch and also an operational amplifier. The non inverting input end of the operational amplifier is used for coupling with input voltage or voltage reference, or used for coupling with the input voltage and the voltage reference; the inverting input end of the operational amplifier is used for coupling with the voltage reference or ground, and the output end thereof is connected with the non inverting input end of the error amplifier.

本发明公开了一种DC/DC电路，包括PWM控制器、电流放大器、峰值电流比较器、误差放大器、主开关和同步开关；还增设运算放大器，其同相输入端用于与输入电压或基准电压耦合，或用于同时与输入电压和基准电压耦合；其反相输入端用于与基准电压或地耦合，其输出端与所述误差放大器的同相输入端连接。

A novel zero-voltage and zero-current resonant pole soft-switching inverter was proposed to achieve zero- voltage and zero-current switching simultaneously when main power devices turn-on and turn-off. Therefore, turn-on capacitive losses could be reduced for devices which the intrinsic capacitor value cannot be neglected. Additionally losses caused by the tail current can also be reduced, when IGBTs are used as main switches.

提出一种新型的零电压零电流谐振极型软开关逆变器，可以在主功率器件开通和关断时，同时实现零电压和零电流，因此对于内部电容不能忽略的器件，可减小容性开通损耗，当绝缘栅双极型晶体管(insulated gate bipolar transistor，IGBT)作为主功率器件时，也可减小拖尾电流引起的损耗。

Current is induced in the secondary coil by passing a current through the primary coil .

电流通过主线圈时在次级线圈中产生电流。

That is, the motor winding capacitance in series with the Deputy, due to the role of the capacitor, so that Kim winding current phase ahead of the main winding current in phase 90 °, in accordance with the basic theory of motor learning: When the space two winding axis position is 90 °, and the flow of two windings of the current phase and poor 90 °, its synthesis must be for the rotating magnetic field, magnetic field, so that motor up and running.

这种电动机就是将电容与副绕组串联，由于电容器的作用，使副相绕组中电流的相位超前于主绕组中电流的相位90°，按照电机学的基本理论：当空间两绕组轴线位置为90°，且流入两绕组中的电流相位又差90°时，其合成磁场必为旋转磁场，从而使电机启动和运转。

The composition voltage, the electric current double closed loop voltage-stabilized source, used the integrated phase shifting crystal thyratron module to do for the electrical energy transformation component, in detail has calculated the rectification main circuit main component parameter; In the pulse-duration modulation part, used the special-purpose integrated circuit to realize the frequency modulation to adjust the pressure, did take IGBT as the power transformation component, realized the output voltage frequency modulation to adjust the pressure, and has calculated the related parameter.

在调压稳压电压源设计中采用二阶工程设计法设计了电压和电流调节器，组成电压、电流双闭环稳压电源，采用集成移相晶闸管模块做为电能变换器件，详细计算了整流主电路主要器件的参数；在脉宽调制部分，采用专用集成电路实现了调频调压，以 IGBT 做为功率变换器件，实现了输出电压的调频调压，并计算了有关参数。

MC44144 Pinout: Flyback and Synchronous Rectifier Apps Provides Complementary Auxiliary Driver with Programmable Deadtime (Turn-On Delay) between AUX and MAIN Switches Peak Current-Mode Control with 0.5-V Cycle-by-Cycle Current Limiting Hiccup Mode 0.75-V Current Limit TrueDrivet 2-A Sink, 2-A Source Outputs 110-V Input Startup Device Trimmed Internal Bandgap Reference for Accurate Line UV and Line OV Threshold Programmable Slope Compensation High-Performance 1.0-MHz Synchronizable Oscillator with Internal Timing Capacitor Precise Programmable Maximum Duty Cycle PB-Free Lead Finish Package

MC44144引脚说明：反激式同步整流和应用服务提供补充辅助与可编程死区时间之间的辅助和主开关峰值电流模式控制0.5 - V的逐周期电流限制打嗝模式0.75 - V的电流限制TrueDrivet 2 - A号水槽，2 -阿源精确的线路过压阈值线UV和可编程斜率补偿高性能1.0 - MHz的振荡器可同步输出110 V输入启动装置边内部带隙基准，内置精密程控定时电容最大占空比无铅引脚完成包

By means of the study of three types of main-switch, it shows that the circuit inductance of the modified ring-small disk main-switch supported by parallel metal bars is feasible to achieve appropriate main current.

经过对三种主开关结构进行实验研究，结果表明：改进的并联金属棒支座圆环-小圆盘型主开关的导通电感比较合适，可产生较好的主脉冲电流。

From the burden increased aspect clarify set upthe necessity of station, then pass to drew up to set up generalizeof transformer substation and line direction to consider, and passto analysis of carry the data, safety, economic and dependableconsider and made sure the 110 kV, 35 kV, 10 kV and station useelectricity of lord connect line, then again through burdencalculation and power supply scope made sure main number, capacityand model number of the transformer set, also in the meantime makesure the station uses capacity and model number of transformer,end, according to biggest keep on work electric current and shortcircuit calculating of calculation result, to the high pressureRong break a machine, insulate a switch, female line, insulate sonand wear a wall set tube, electric voltage with each other feelingmachine, electric current with each other the feeling machinecarried on choose a type, thus completed a 110 kV electricity apart of design.

本文首先根据任务书上所给系统与线路及所有负荷的参数，分析负荷发展趋势。从负荷增长方面阐明了建站的必要性，然后通过对拟建变电站的概括以及出线方向来考虑，并通过对负荷资料的分析，安全，经济及可靠性方面考虑，确定了110kV ，35kV ，10kV 以及站用电的主接线，然后又通过负荷计算及供电范围确定了主变压器台数，容量及型号，同时也确定了站用变压器的容量及型号，最后，根据最大持续工作电流及短路计算的计算结果，对高压熔断器，隔离开关，母线，绝缘子和穿墙套管，电压互感器，电流互感器进行了选型，然后进行配电装置和平面布置的设计以及防雷的设计，从而完成了110kV 电气一次部分的设计。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。