电气专业英语论文5000字

电气专业英语论文5000字

Fire Fighting
Along with the our country economic development rapid development, the lives of the people level unceasing enhancement, the city uses to be day by day anxious, urges the building to face the direction is developing. This kind of high level civil construction repair needed materials and the way also more hasten the diversification, and along with uses electricity the load and coal gas consumption quantity enlarging, proposed to the fire auto-alarm system design is higher, a stricter request. In order to guarantee the people life and property the security, the fire auto-alarm system design has become in the high level civil construction design one of most important design contents. Presently based on the author fire of auto-alarm system design overseeing work in the high level civil building experience, proposed in present national related standard and standard unclear true detail shallow opinion, by for the colleagues to discuss and to point out mistakes.
First, design basis
The fire auto-alarm system design is a specialized very strong technology work, at the same time also has the very strong policy-type. Therefore, first should be clear about the following design basis:
1st, must grasp the architectural design fire protection standard, the system design standard, the equipment manufacture standard, the installment construction approval standard and the administration laws and regulations and so on five big aspects fire laws and regulations, and in practical understanding present country related standard and standard positive word: "Must", "be supposed", "to be suitable", "may" and the reverse side word: "Strictly prohibits", "should not", "not have", "not to be suitable" the meaning.
2nd, must aim at high level civil building function, use and the protection object fire protection rank, earnestly carries out the present national related standard and the standard, earnestly treats the public security fire prevention surveillance department the examination and approval opinion.
Second, fire auto-alarm system equipment establishment
Fire detector establishment
Opens wide either the seal or the stair hall should alone divide the search coverage, and each 2 ~ 3 establish a fire detector.

The first room (including guards against in front of smoke stair hall in front of room, fire elevator room, fire elevator with guards against the front room which smoke stair hall comes in handy) and the aisle should distinguish alone to divide the search coverage, specially front the room and the lift well, the scattered stair hall and the aisle are interlinked, has time the fire haze to be easier to gather or to flow, is the personnel disperses which saves goal with the fire prevention, therefore should install the fire detector. Regarding common elevator in front of room although is not the personnel disperses , but this front room and the lift well are interlinked, has time the fire haze to be also easy to gather or to flow, suitably alone divides the search coverage and installs the fire detector.
The electric cable shaft therefore is easy to form pulls out the smoke inflammation the channel; Has when the fire the fire intensity not easily extends along the electric cable burns, for this, "the high level civil construction design fire protection standard" and "the civil construction electricity design standard" separately proposes the detailed specific stipulation in the construction and in the electric wire or on the electric cable shaping. But considered implements specifically the difficulty and the present situation, the electric cable shaft installs the fire detector is extremely essential, and coordinates the shaft the fire protection separation request, each 2 ~ 3 or each level installs.
The elevator machine room should install the fire detector, its elevator is the important vertical transportation vehicle; Its two elevator machine room has has the fire risk; Its three lift well existence essential opens the hole, like the level gate opens between the hole, the air vent, the between permanence opens the hole with the elevator machine room or the pulley and so on; Its four when has the fire, the lift well often becomes the fire intensity spread the channel, is easy to threaten the elevator machine room the facility. Therefore, the elevator machine room establishes the fire detector is necessary, crown of also suitable establishment fire detector lift well.
2nd, the manual fire reports to the police the button establishment
(Including guards against in front of smoke stair hall in view of various floors front room in front of room, fire elevator room, fire elevator with guards against which smoke stair hall to come in handy the front room) is has when the fire the personnel to disperse which saves goal with fire prevention, should report to the police the button first choice spot as the establishment manual fire. In addition, the room also should establish the manual fire to the common elevator in front of to report to the police the button.
In the public active place (including hall, hall, dining room, multi-purpose hall and so on) and the main thoroughfare and so on place, the personnel very is all centralized, and mainly disperses the channel. Therefore should report to the police the button in these public active places main access establishment manual fires; The manual fire establishes which in the main thoroughfare reports to the police the button to guarantee "to a manual fire which most is close to reports to the police the button distance from a fire protection district any position not to be supposed to be bigger than 30 meters".
3rd, the fire emergency broadcasts the speaker the establishment

The aisle, the hall, the dining room and so on the public place personnel very are all centralized, and mainly disperses the channel. Therefore should press in these public places "to a recent speaker distance is not bigger than 25 meters from a fire protection district any spot" and "in the aisle last should not be bigger than 12.5 meters the speaker to the aisle terminal distance" the establishment fire emergency to broadcast the speaker; Next also should establish the fire in the public bathroom place emergency to broadcast the speaker.
The first room (including guards against in front of smoke stair hall in front of room, fire elevator room, fire elevator with guards against which smoke stair hall to come in handy the front room) is has when the fire the personnel to disperse which saves goal with fire prevention, also has the fire door separation and the sounds of people is confused and noisy, therefore should establish the fire emergency to broadcast the speaker. In front of the common elevator the room also should establish the fire emergency to broadcast the speaker. Disperses the stair hall also is has when the fire the personnel to disperse which saves goal with the fire prevention, also the sounds of people are confused and noisy, therefore should establish the fire emergency to broadcast the speaker, by favors the fire emergency broadcast to disperse the instruction.
4th, fire alarm installment establishment
The establishment fire emergency broadcast fire auto-alarm system, the author thought also should install the fire alarm installment, but its control procedure should be: The alarm apparatus should confirm after the fire, uses manual or the automatic control mode unification to the fire correlation region transmission warning, stops the alarm apparatus work in the stipulation time, the rapid linkage fire emergency broadcast and broadcasts to the people disperses the instruction.
The fire alarm installment establishment position, the author thought should report to the police the button position with the manual fire to be same, its wall surface installment should for be apart from the ground 1.8 meters highly

5th, fire special use telephone establishment
Installs the fire special use telephone extension telephone, should be located the engine room which related also some people is on duty frequently with the fire linkage control (including fire water plant, spare electricity generation engine room, matches substation, mainly ventilates with air conditioning engine room, discharges fume engine room, fire prevention elevator machine room and other), the fire fighting control system operates the equipment place or the control room, the fire duty officers observation room, the security manages spot and so on public room. Sedan of theater box the fire elevator and in the ordinary elevator all should suppose the special use telephone, requests the elevator machine room and the elevator sedan theater box, the elevator machine room and the fire control room, the elevator sedan theater box and the fire control room and so on three compositions is reliable to speaks the correspondence telephone system. Usually in fire control room; The establishment elevator monitoring demonstration plate (including position indicator, direction indicating lamp, to speaks correspondence telephone, trouble lamp and so on), in order to carries on the necessity to the elevator running status which in the surveillance and the emergency case controls.
Is equipped with the manual fire to report to the police position and so on button, fire hydrant button also should install the fire special use telephone receptacle.
Third, fire linkage control
1st, the fire linkage control should include the control fire pump to open, to stop, also should demonstrate opens pumps the button the position and the fire pump work and the malfunction. When the fire hydrant is equipped with the fire hydrant button, its electric installation work spot also should demonstrate the fire pump the working mode active status (namely establishment fire pump work indicating lamp).
2nd, the fire linkage control should include the control spraying of water and the water atomization fire fighting system opens, stops, also should demonstrate the fire pump the work and the malfunction and the fluent display, reports to the police the valve, the safety signal valve working mode active status. In addition, to the basin, the water tank water level also should carry on the demonstration monitor; In order to prevent the overhaul signal valve is shut down, the author thought should use the belt electric signal the control signal valve by to demonstrate it opens the condition.
3rd, the fire linkage control other controls and the demonstration function, should carry out the present national related standard and the standard specific stipulation.

Fourth, fire auto-alarm system wiring
In order to prevent the fire occurs when the fire control, the correspondence and the warning line severance, causes the fire fighting work to be unable to carry on, creates the bigger economic loss; Also for the suppression electronmagetic interference (for example transformer, electric motor, electric cable and so on) the influence which produces to the fire auto-alarm system. The fire auto-alarm system transmission line and the fire control, the correspondence and the warning line should use the being flame-resistant electric cable, and should use the metal tube or the enclosed metal trunking protection. The fire manual positive governing installment line should use the fireproof electric cable, its electric cable also should use the metal tube or the enclosed metal trunking protection. Uses Ming Fushi, should takes the fire protection protective measures on the metal tube or the enclosed metal , concluding remark
The author rests on the concrete project to implement the experience, elaborated the design basis, fire auto-alarm design actual problem and so on system equipment establishment, fire linkage control and its wiring pulls out some shallow opinions, its goal is enhances the fire auto-alarm system the design quality, discovered early and the notification fire, prevented and reduces the fire to harm, by protects the person and the property safety.

消防
随着我国经济发展快速发展，人民生活的水平不断提高，城市使用是每天着急，敦促建设面临着发展的方向。这种高层次的民间建筑维修所需的材料和方式也更加多样化加快，而且随着使用电力负荷和煤气消费量扩大，提议消防自动报警系统设计较高，更严格的要求。为了保证人民生命和财产的安全，消防自动报警系统的设计已经成为在高级别民间建筑设计的一个最重要的设计内容。目前的基础上撰文火灾自动报警系统设计监督工作的高层次的民间建设的经验，建议在目前国家相关标准和标准不清楚真正详细浅见解，为同事们的讨论，并指出错误。
首先，设计依据
火灾自动报警系统的设计是一家专业非常强的技术工作，同时还具有很强的政策性。因此，首先应明确以下设计依据：
第一，必须紧紧抓住的建筑设计防火标准，该系统的设计标准，标准的设备制造，安装施工审批标准和管理的法律和规章等五大方面的消防法律法规，并在实际了解国家有关本标准和标准积极字： “必须” ， “必须假定” ， “不适合” ， “可能”和反面词： “严格禁止” ， “不应该” ， “没有” ， “不适合“的含义。
第二，必须着眼于高层次的民间建筑的功能，利用和保护对象的防火等级，认真开展本标准和国家有关标准，认真对待公安防火监督部门的审批意见。
其次，火灾自动报警系统设备的建立
建立火灾探测器
要么全打开的印章或楼梯大厅应单独划分搜索范围，每个2 〜 3建立火灾探测器。

第一个房间（包括防前面的烟雾大厅楼梯前室，消防电梯间，消防电梯防前面房间烟雾楼梯大会堂来用场）和过道应区分单独划分搜索范围，特别是前面的房间，以及电梯，分散楼梯大厅和走道都是相互关联的，有时间的火灾烟雾比较容易收集或流动，是人员分散保存目标与防火，因此，应该安装火警探测器。关于共同电梯前室虽然不是人员分散，而且这方面的空间和良好的电梯是相互关联的，有时间的火灾烟雾也很容易被收集或流动，适当地划分为单独的搜索覆盖面和安装消防探测器。
电缆轴因此很容易形成掏出烟炎症渠道，拥有火灾时的火强度不容易延伸沿电缆燃烧，为此， “高级别民间建筑设计防火标准”和“民用建筑电气设计标准“分别提出了详细具体的规定，在建筑和在电线或电缆塑造。但认为具体实施的难度和目前的情况下，电缆竖井安装了火灾探测器是非常必要的，坐标轴的防火分隔要求，每2 〜 3或每一级安装。
电梯机房应安装火灾探测器，它的电梯是重要的垂直交通工具，其两个电梯机房已具有火灾危险性，其存在的三个基本解除以及打开洞，像打开闸门的水平之间的球洞，在气孔，持久的关系打开了洞与电梯机房或滑轮等，其时，有四个火，升降机以及往往成为火灾强度传播渠道，很容易危及电梯机房设施。因此，电梯机房建立了火灾探测器是必要的，也适用于皇冠建立火灾探测器举井。
2 ，手动火警报警按钮建立
（包括防前面的烟雾楼梯大厅鉴于各层前房间前面的房间，消防电梯间，消防电梯防这些烟雾楼梯大会堂派上用场前室）是有火灾时人员驱散节省目标，防火，应立即向警方举报的按钮，首选地点设立手动火警。此外，该室也应建立防火手册的共同电梯前，向警方报案的按钮。
在公共活动场所（包括会堂，礼堂，餐厅，多功能厅等）和主要通道等场所，是所有工作人员非常集中，主要是分散的渠道。因此，应立即向警方举报的按钮，在这些公共活动场所主要通道设立手册火灾;该手册规定的火灾中的主要通道报警按钮，以保证“ ，以手动火警最接近报警按钮距离防火区的任何位置不应该超过30米。 “
第三，消防紧急广播喇叭建立

走道，大厅，餐厅等公共场所的工作人员都非常集中，主要是分散的渠道。因此，应该按这些公共场所的“最近的一项发言距离不超过25米的防火保护区的任何位置”和“在走道上不应大于十二点五米扬声器的过道末端距离”建立消防应急广播喇叭;下一步还应当建立消防在公共浴室的地方紧急广播喇叭。
第一个房间（包括防前面的烟雾大厅楼梯前室，消防电梯间，消防电梯防这些烟雾楼梯大会堂派上用场前室）是有火灾时的人员驱散节省目标与防火，也有分离和防火门的声音，人民的混乱和嘈杂，因此，应建立消防应急广播喇叭。在前面的共同电梯房也应建立消防应急广播喇叭。分散大厅楼梯也已经火灾时的人员驱散节省目标与防火，也是人民的声音和嘈杂的混淆，因此应建立消防应急广播喇叭，由主张消防紧急广播驱散指令。
第四，建立火灾报警装置
建立消防应急广播火灾自动报警系统，笔者认为还应该安装消防报警装置，但它的控制程序应该是：该报警器应确认火灾后，利用手动或自动控制模式统一消防相关区域传输预警，报警器停止工作时间的规定，迅速联系消防应急广播和电视节目，并且分散了人们的指示。
火警警报装置建立的立场，笔者认为应该向警方报案的按钮位置的手动火警是相同的，它的墙面安装应为距地面1.8米高度

第五，消防专用电话设立
安装消防专用电话分机电话，应设机房其中也涉及一些人是在工作地点经常与消防联动控制（包括消防给水设备，备件发电机房，火柴变电站，主要ventilates空调引擎室，排放烟气轮机室，防火电梯机房及其他） ，消防控制系统的经营场所或设备的控制室，消防责任人员观察室，现场的安全管理等公共空间。轿车的影院中消防电梯和普通电梯应假设所有使用的特殊电话，请电梯机房和电梯轿车影院中，电梯机房及消防控制室，电梯轿车影院方块和消防控制室等三个成分是可靠的讲通信电话系统。通常在消防控制室;建立电梯监测演示板（包括位置指示器，显示方向灯，以讲信函电话，麻烦灯等） ，以进行必要的电梯在运行状态的监视和紧急情况下的控制。
配备了手动火警报警位置等按钮，消火栓按钮，还应该安装消防专用电话插座。
第三，消防联动控制
第一，消防联动控制应包括控制消防泵开启，停止，也应表现出的按钮，打开泵的位置和消防泵的工作和故障。当消火栓设有消火栓按钮时，其电气安装工程现场也应表现出的消防泵的工作模式有效状态（即建立消防泵工作表明灯） 。
第二，消防联动控制应包括控制喷洒水和水雾化灭火系统打开，停止，也应表现出的消防泵的工作和故障和流利显示，报警阀，安全信号阀工作模式积极的地位。此外，该盆地，水箱水位也应进行示范监测;为了防止检修信号阀关闭，作者认为应该使用带电信号控制信号阀证明它打开条件。
第三，消防联动控制其他控制和示范作用，应进行本标准和国家有关标准的具体规定。

第四，火灾自动报警系统布线
为了防止火灾发生时，消防控制，通信和警戒线遣散，使灭火工作无法进行，造成了更大的经济损失，也为抑制electronmagetic干扰（例如变压器，电电机，电缆等）的影响而产生的火灾自动报警系统。火灾自动报警系统的输电线路和消防控制，通信和预警线应使用被阻燃电缆，并应使用金属管或封闭式金属线槽保护。消防手册积极理事分期付款行应使用防火电缆，其电缆也应使用金属管或封闭式金属线槽保护。使用明复，应采取防火保护措施的金属管或封闭金属 ，结论备注
作者取决于具体的项目实施经验，阐述了设计依据，火灾自动报警设计和实际问题，以便建立系统设备，消防联动控制及其接线拿出一些肤浅的意见，其目的是增强了火灾自动报警系统的设计质量，早期发现，并通知消防，预防和减少火灾危害，通过保护个人和财产安全。

求电气工程及其自动化英文论文一篇 内容不限 题目要翻译好 谢谢

用于分布式在线UPS中的并联逆变器的一种无线控制器
A Wireless Controller for Parallel Inverters in Distributed Online UPS Systems
Josep M. Guerrero', Luis Garcia de Vicufia", Jose Matas'*, Jaume Miret", and Miguel Castilla"
. Departament #Enginyeria de Sistemes, Automatica i Informhtica Industrial. Universitat Polithica de Catalunya
C. Comte d'Urgell, 187.08036 -Barcelona. Spain. Email: .. Departament #Enginyeria Electrbnica. Universitat Polit6cnica de Catalunya
AV. Victor BaLguer s/n. 08800I - Vilanova i la Geltrh. Spain
Absiract - In this paper, a novel controller for parallelconnected
online-UPS inverters without control wire
interconnections is presented. The wireless control technique is
based on the well-known droop method, which consists in
introducing P-oand Q-V schemes into the inverters, in order to
share properly the power drawn to the loads. The droop method
has been widely used in applications of load sharing between
different parallel-connected inverters. However, this method
has several drawbacks that limited its application, such as a
trade-off between output-voltage regulation and power sharing
accuracy, slow transient response, and frequency and phase
deviation. This last disadvantage makes impracticable the
method in online-UPS systems, since in this case every module
must be in phase with the utility ac mains. To overcome these
limitations, we propose a novel control scheme, endowing to the
paralleled-UPS system a proper transient response, strictly
frequency and phase synchronization with the ac mains, and
excellent power sharing. Simulation and experimental results
are reported confirming the validity of the proposed approach.
1. INTRODUCTION
The parallel operation of distributed Uninterruptible Power
Supplies (UPS) is presented as a suitable solution to supply
critical and sensitive loads, when high reliability and power
availability are required. In the last years, many control
schemes for parallel-connected inverters has been raised,
which are derived from parallel-schemes of dc-dc converters
[I], such as the master-slave control [2], or the democratic
control [3]. In contrast, novel control schemes have been
appeared recently, such as the chain-structure control [4], or
the distributed control [ 5 ] . However, all these schemes need
control interconnections between modules and, hence, the
reliability of the system is reduced since they can be a source
of noise and failures. Moreover, these communication wires
limited the physical situation ofthe modules [6].
In this sense, several control techniques has been proposed
without control interconnections, such as the droop method.
In this method, the control loop achieves good power sharing
making tight adjustments over the output voltage frequency
and amplitude of the inverter, with the objective to
compensate the active and reactive power unbalances [7].
This concept is derived from the power system theory, in
which the frequency of a generator drops when the power
drawn to the utility line increases [8].
0-7803-7906-3/03/$17.00 02003 IEEE. 1637
However, this control approach has an inherent trade-off
between voltage regulation and power sharing. In addition,
this method exhibits slow dynamic-response, since it requires
low-pass filters to calculate the average value of the active
and reactive power. Hence, the stability and the dynamics of
the whole system are hardly influenced by the characteristics
of these filters and by the value of the droop coefficients,
which are bounded by the maximum allowed deviations of
the output voltage amplitude and frequency.
Besides, when active power increases, the droop
characteristic causes a frequency deviation from the nominal
value and, consequently, it results in a variable phase
difference between the mains and the inverter output voltage.
This fact can be a problem when the bypass switch must
connect the utility line directly to the critical bus in stead of
its phase difference. In [9], two possibilities are presented in
order to achieve phase synchronization for parallel lineinteractive
UPS systems. The first one is to locate a particular
module near the bypass switch, which must to synchronize
the output voltage to the mains while supporting overload
condition before switch on. The second possibility is to wait
for the instant when phase matching is produced to connect
the bypass.
However, the mentioned two folds cannot be applied to a
parallel online-UPS system, since maximum transfer time
ought to be less than a % of line period, and all the modules
must be always synchronized with the mains when it is
present. Hence, the modules should be prepared to transfer
directly the energy from the mains to the critical bus in case
of overload or failure [lo].
In our previous works [11][12], we proposed different
control schemes to overcome several limitations of the
conventional droop method. However, these controllers by
themselves are inappropriate to apply to a parallel online-
UPS system. In this paper, a novel wireless control scheme is
proposed to parallel different online UPS modules with high
performance and restricted requirements. The controller
provides: 1) proper transient response; 2) power sharing
accuracy; 3) stable frequency operation; and 4) good phase
matching between the output-voltage and the utility line.
Thus, this new approach is especially suitable for paralleled-
UPS systems with true redundancy, high reliability and
power availability. Simulation and experimental results are
reported, confirming the validity of this control scheme.
Fig. 1. Equivalenl cimuif ofan invener connecled 10 a bus
t"
Fig. 2. P-odraop function.
11. REVlEW OF THE CONVENTIONAL DROOP METHOD
Fig. 1 shows the equivalent circuit of an inverter connected
to a common bus through coupled impedance. When this
impedance is inductive, the active and reactive powers drawn
to the load can be expressed as
EVcosQ - V2 Q=
where Xis the output reactance of an inverter; Q is the phase
angle between the output voltage of the inverter and the
voltage of the common bus; E and V are the amplitude of the
output voltage of the inverter and the bus voltage,
respectively.
From the above equations it can be derived that the active
power P is predominately dependent on the power angle Q,
while the reactive power Q mostly depends on the outputvoltage
amplitude. Consequently, most of wireless-control of
paralleled-inverters uses the conventional droop method,
which introduces the following droops in the amplitude E
and the frequency U of the inverter output voltage
u = w -mP (3)
E = E ' - n Q , (4)
being W* and E' the output voltage frequency and amplitude
at no load, respectively; m and n are the droop coefficients
for the frequency and amplitude, respectively.
Furthermore, a coupled inductance is needed between the
inverter output and the critical bus that fixes the output
impedance, in order to ensure a proper power flow. However,
it is bulky and increase:; the size and the cost of the UPS
modules. In addition, tho output voltage is highly distorted
when supplying nonlinezr loads since the output impedance
is a pure inductance.
It is well known that if droop coefficients are increased,
then good power sharing is achieved at the expense of
degrading the voltage regulation (see Fig. 2).
The inherent trade-off of this scheme restricts the
mentioned coefficients, which can be a serious limitation in
terms of transient response, power sharing accuracy, and
system stability.
On the other hand, lo carry out the droop functions,
expressed by (3) and (4), it is necessary to calculate the
average value over one line-cycle of the output active and
reactive instantaneous power. This can be implemented by
means of low pass filters with a smaller bandwidth than that
of the closed-loop inverter. Consequently, the power
calculation filters and droop coefficients determine, to a large
extent, the dynamics and the stability of the paralleledinverter
system [ 131.
In conclusion, the droop method has several intrinsic
problems to be applied 1.0 a wireless paralleled-system of
online UPS, which can he summed-up as follows:
Static trade-off between the output-voltage regulation
(frequency and amplitude) and the power-sharing
accuracy (active an4d reactive).
2) Limited transient response. The system dynamics
depends on the power-calculation filter characteristics,
the droop coefficients, and the output impedances.
Lost of ac mains synchronization. The frequency and
phase deviations, due to the frequency droop, make
impracticable this method to a parallel-connected
online UPS system, in which every UPS should be
continuously synchronized to the public ac supply.
1)
3)
111. PROPOSED CONTROL FOR PARALLEL ONLINE UPS
INVERTERS
In this work, we will try to overcome the above limitations
and to synthesize a novel control strategy without
communication wires that could be appropriate to highperformance
paralleled industrial UPS. The objective is to
connect online UPS inverters in parallel without using
control interconnections. This kind of systems, also named
inverter-preferred, should be continuously synchronized to
the utility line. When an overload or an inverter failure
occurs, a static bypass switch may connect the input line to
the load, bypassing the inve:rter [14][15].
Fig. 3 shows the general diagram of a distributed online
UPS system. This system consists of two buses: the utility
bus, which is connected lo the public ac mains; and the
secure bus, connected to the distributed critical loads. The
interface between these buses is based on a number of online
UPS modules connected in parallel, which provides
continuously power to the: loads [16]. The UPS modules
include a rectifier, a set of batteries, an inverter, and a static
bypass switch.
1
1638
Q ac mains
utility bus
I I I
j distributed loads !
Fig. 3. Online distributed UPS system.
syposr /
I 4
(4
Fig. 4. Operation modes of an online UPS.
(a) Normal operation. (b) Bypass operation. (c) Mains failure
The main operation modes of a distributed online UPS
1) Normal operation: The power flows to the load, from
the utility through the distributed UPS units.
2) Mains failure: When the public ac mains fails, the
UPS inverters supply the power to the loads, from the
batteries, without disruption.
Bypass operation: When an overload situation occurs,
the bypass switch must connect the critical bus
directly to the ac mains, in order to guarantee the
continuous supply of the loads, avoiding the damage
of the UPS modules.
For this reason, the output-voltage waveform should be
synchronized to the mains, when this last is present.
system are listed below (see Fig. 5):
3)
Nevertheless, as we state before, the conventional droop
method can not satisfy the need for synchronization with the
utility, due to the frequency variation of the inverters, which
provokes a phase deviation.
To obtain the required performance, we present a transient
P-w droop without frequency-deviation in steady-state,
proposed previously by OUT in [ 111
w=o -mP (5)
where is the active power signal without the dccomponent,
which is done by
. -
I t -1s
P= p ,
( s + t - ' ) ( s + o , )
being zthe time constant of the transient droop action.
The transient droop function ensures a stable frequency
regulation under steady-state conditions, and 'at the same
time, achieves active power balance by adjusting the
frequency of the modules during a load transient. Besides, to
adjust the phase of the modules we propose an additional
synchronizing loop, yielding
o=w'-m%k,A$, (7)
where A$ is the phase difference between the inverter and the
mains; and k, is the proportional constant of the frequency
adjust. The steady-state frequency reference w* can be
obtained by measuring the utility line frequency.
The second term of the previous equality trends to zero in
steady state, leading to
w = w' - k4($ -@'), (8)
being $and $* the phase angles of the output voltage inverter
and the utility mains, respectively.
Taking into account that w = d $ / d t , we can obtain the
next differential equation, which is stable fork, positive
d$ *
dt dt
- + km$ = - + k,$' . (9)
Thus, when phase difference increases, frequency will
decrease slightly and, hence, all :he UPS modules will be
synchronized with the utility, while sharing the power drawn
to the loads.
IV. CONTROLLIEMRP LEMENTATION
Fig. 5 depicts the block diagram of the proposed
controller. The average active power P , without the dc
component, can be obtained by means of multiplying the
output voltage by the output current, and filtering the product
........................................................................................
io
",.
L
Sj'nchronirorion loop
.......................................................................................
Fig. 5. Block diagram of the proposed controller.
using a band-pass filter. In a similar way, the average
reactive power is obtained, hut in this case the output-voltage
must be delayed 90 degrees, and using a low-pass filter.
In order to adjust the output voltage frequency, equation
(7) is implemented, which corresponds to the frequency
mains drooped by two transient-terms: the transient active
power signal term; and the phase difference term, which
is added in order to synchronize the output voltage with the
ac mains, in a phase-locked loop (PLL) fashion. The outputvoltage
amplitude is regulated by using the conventional
droop method (4).
Finally, the physical coupled inductance can be avoided by
using a virtual inductor [17]. This concept consists in
emulated an inductance behavior, by drooping the output
voltage proportionally to the time derivative of the output
current. However, when supplying nonlinear loads, the highorder
current-harmonics can increase too much the outputvoltage
THD. This can be easily solved by using a high-pass
filter instead of a pure-derivative term of the output current,
which is useful to share linear and nonlinear loads [I 1][12].
Furthermore, the proper design of this output inductance can
reduce, to a large extent, the unbalance line-impedance
impact over the power sharing accuracy.
v. SIMULATION AND EXPERIMENTARELS ULTS
The proposed control scheme, (4) and (7), was simulated
with the parameters listed in Table 1 and the scheme shown
in Fig. 6, for a two paralleled inverters system. The
coefficients m, n, T, and kv were chosen to ensure stability,
proper transient response and good phase matching. Fig. 7
shows the waveforms of the frequency, circulating currents,
phase difference between the modules and the utility line,
and the evolution of the active and reactive powers. Note the
excellent synchronization between the modules and the
ACmiiinr 4 j. ...L...I.P...S...1... ..........................B...u...n...r.r..r..e..s... ................................... i
Fig. 6. Parallel operation oftwa online UPS modules,
mains, and, at the same time, the good power sharing
obtained. This characteristik let us to apply the controller to
the online UPS paralleled systems.
Two I-kVA UPS modules were built and tested in order to
show the validity of the proposed approach. Each UPS
inverter consisted of a single-phase IGBT full-bridge with a
switching frequency of 20 kHz and an LC output filter, with
the following parameters: 1. = 1 mH, C = 20 WF, Vi" = 400V,
v, = 220 V, I50 Hz. The controllers of these inverters were
based on three loops: an inner current-loop, an outer PI
controller that ensures voltage regulation, and the loadsharing
controller, based on (4) and (7). The last controller
was implemented by means of a TMS320LF2407A, fixedpoint
40 MHz digital sigrial processor (DSP) from Texas
Instruments (see Fig. 8), using the parameters listed in Table
I. The DSP-controller also includes a PLL block in order to
synchronize the inverter with the common bus. When this
occurs, the static bypass switch is tumed on, and the droopbased
control is initiated.
1640
big 7 Wa\cfc)rms for r, ;mnectcd in parallel. rpchrontred io Ihc ac mdnl.
(a) Frequencics ufhoth UPS (b) Clrculattng currcni among modulcs. (CJ Phmc d!Nercn;: betucen ihc UPS a#>dth e ai mum
(d) Ikiril uf the phze diNmncc (e) md (0 Activc and rcactlw pouerr "I ooih UPS
Note that the iimc-acs arc deliheratcly JiNercni due in thc disiinct timuion*uni) ofthe \ inrblrr
1641
TABLEI.
PARAMETEROSF THE PARALLELESDYS TEM.
Filter Order I I
Filter Cut-off Frequency I 0, I 10 I rags
Fig. 8 shows the output-current transient response of the
UPS inverters. First, the two UPS are operating in parallel
without load. Notice that a small reactive current is circling
between the modules, due to the measurement mismatches.
Then, a nonlinear load, with a crest factor of 3, is connected
suddenly. This result shows the good dynamics and loadsharing
of the paralleled system when sharing a nonlinear
load.
Fig. 8. Output current for the two paralleled UPS, during the connection of B
common nonlinear load with a crest factor of 3. (Axis-x: 20 mddiv. Axis-y:
5 Mdiv.).
VI. CONCLUSIONS
In this paper, a novel load-sharing controller for parallelconnected
online UPS systems, was proposed. The controller
is based on the droop method, which avoids the use of
control interconnections. In a sharp contrast with the
conventional droop method, the controller presented is able
to keep the output-voltage frequency and phase strictly
synchronized with the utility ac mains, while maintaining
good load sharing for linear and nonlinear loads. This fact let
us to extend the droop method to paralleled online UPS.
On the other hand, the proposed controller emulates a
special kind of impedance, avoiding the use of a physical
coupled inductance. Th.e results reported here show the
effectiveness of the proposed approach.

急求一篇与电气专业有关的英语论文（带翻译）2000字以上，，高分悬赏！！

童鞋你好！
这个估计需要自己搜索了！
网上基本很难找到免费给你服务的！
我在这里给你点搜索国际上常用的外文数据库：
----------------------------------------------------------
❶ISI web of knowledge Engineering Village2
❷Elsevier SDOL数据库 IEEE/IEE(IEL)
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中文翻译得自己做了，实在不成就谷歌翻译。
弄完之后，自己阅读几遍弄顺了就成啦！
学校以及老师都不会看这个东西的！
外文翻译不是论文的主要内容！
所以，很容易过去的！
祝你好运！

求一篇英文的电气专业的论文最好带上翻译谢谢

好问题。
已经到了阅读专业英语的水平就不能用翻译。翻译只能降级，达不到原文的深度。

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交流电机的SVPWM控制系统的设计
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为基础的研究
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