LCI原理1

LCI 原理

(50/51 device), Lock out (86) relay etc are normally used.

通常使用的保护继电器有过流，反时限过流(50/51设备)继电器，锁定(86)继电器。

5.Addition devices on switchgear Metering such as line voltage and line current meters. protective and monitoring module such as Multilin module.

断路器辅助设备电压表和电流表保护和监控模块如Multilin

6.For Tanggang application, parallel 12 pulse configuration is used without 6 pulse mode, one source breaker is placed in front of the three windings transformer.

唐钢使用的是并联12脉冲而不是6脉冲模式，变压器前只有一个源侧断路器。 7.Interface of the system elementary

a. SWGR relay is configurated such that relay energized to trip switchgear and de-energized to permit to close the switchgear. Use SWGR N.C. contact to permit to close circuit, and N.O. contact to trip circuit.

a.SWGR继电器的设计是，继电器得电断开断路器，失电允许闭合断路器。SWGR的常闭点用在合闸回路，常开点用在跳闸回路。

b. Closing the switchgear is done at remote operator station through MSC logic. b.在遥控模式下，通过MSC逻辑控制使断路器闭合。

c. It is recommended to close the switchgear when it is ready (drive not running) so that the LCI control will lock on the source side PLL to get ready to start anytime.

c.建议断路器准备好（驱动没有运行）时就闭合它，这样LCI控制可以锁定源侧PLL，做好随时起动的准备。

d. Switchgear status contact feedback to LCI control, see sh. 1EK of system elementary.

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LCI 原理

Switchgear 52A contact (contact closes when switchgear closed) in series with 86 (LOR) contact (contact open when switchgear is told to trip) are wired back to LCI control highr speed I/O TB2-X9 for LCI sequencing control.

d.断路器状态信号反馈至LCI的图纸见系统原理图1EK页。断路器52A（断路器闭合时接触器闭合）与86（LOR）触点（断路器被告知跳闸时打开）接回到了LCI顺序控制的高速I/O的highr speed I/O TB2-X9。

e. Sensing the 86-LOR device status by the LCI control is important. The 86-LOR device originates external tripping actions. There are circumstance that external (not originated from LCI) switchgear trips (from 50/51 device, 52CS operator trip handle or any trip source other than LCI control), cause severe arcing if the switchgear has to interrupt heavy current. With the help of the 86 contact, the LCI control would do its best to call for inversion limit firing at both bridges (source and load) to shut off (extingush) current before the tips of the breaker starts to open.

e.LCI控制知道86-LOR装置的状态非常重要。86-LOR装置引起外部跳闸动作。如果断路器不得不中断大电流时，外部（不是来自LCI）使断路器跳闸（来自５０／５１装置，５２ＣＳ操作员跳闸处理或任何跳闸源而不是ＬＣＩ控制）将引起严重的变形。有了８６接触器的帮助，ＬＣＩ将能够很好的调用两个桥（源侧和负载侧）的反限制触发，在断路器跳闸准备打开之前关断电流。

The contacts from the 86 relay goes to the LCI and switchgear trip circuit at the same time. After the switchgear trip relay acknowledges the action, it normally takes 3 cycles or more for the tip of the switchgear to start to open. It takes only about half cycle for the LCI control to zero the drive current. Therefore the switchgear opens under no current and minimizes impact to the switchgear as well as the equipment in the drive (mainly SCRs).

86继电器同时将其触点发送给LCI系统和断路器跳闸回路。当断路器跳闸继电器允许跳闸后，它一般在3个扫描周期或更晚些开始断开断路器，LCI系统大约

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LCI 原理

需半个扫描周期将回路电流减少至0。因此，当断路器断开时，LCI系统回路中已没有电流，对系统设备的冲击降到最小（主要是可控柜件）。

Source Isolation Transformer源侧隔离变压器

1.The source isolation transformer provides isolation from the AC system. It also provides the correct voltage level at the terminals of the LCI source bridge. It also provides additional system impedance to limit the magnitude of any downstream bus fault for the fuseless LCI power conversion bridge.

源侧隔离变压器提供了与交流系统的隔离，为ＬＣＩ源侧桥提供了正确的电压等级，还为ＬＣＩ功率转换桥提供了额外的系统阻 抗，来限制母线故障。

2.The transformer is designed to supply power to a 3-phase, full wave thyristor bridge connected to an inductive DC load. The AC current to the bridge will be approximately rectanglar with 120 degree conduction and the following magnitude of harmonic current:

变压器被设计提供３相全波可控硅桥连接到感性直流负载。去桥的交流电流被近似的分解成１２０度方波，并伴随谐波电流。

Harmonic Order谐波次序 1 5 7 11 13 17 19 23 25 % of RMS Winding Current 均方根绕组电流％ 96 20 14 9 7 5 4 3 2 11页

LCI 原理

3.The transformer KVA rating is determined to supply power to accelerate the motors from standstill to full speed and transfer from start bus to run bus within 2 minutes.

变压器额定容量取决于供电电源，电源使电机在2分钟之内从静止加速到全速，从起动母线切换到运行母线。

4.The primary winding is delta connected with a no-load tap changer. Standard taps are four full capacity 2.5% taps, 2 above , 2 below rated voltage. Taps to provide high secondary voltage are used only when the incoming voltage is expected to be 95% or less. The primary voltage is determined by the user's source feeder voltage.

一次侧绕组是三角形接法，具有无载分接头开关。标准分头接法是4个全容量2.5%分头，2个高于，2个低于额定电压。当进线电压约为95%或更少时，一般使用提供高二次侧电压的分头。一次侧电压取决于用户的源侧电压。

5.On six pulse drives, the secondary is normally supplied delta connected. Continuous operating voltage to ground is 1. 25 times rated line to line voltage.

六脉冲驱动的二次侧通常提供三角形接法。对地连续操作电压是额定线对线电压的1.25倍。

6.For parallel 12 pulse source without 6 pulse operation as in Tanggang, the transformer has three windings, one (delta connected) for primary and two for secondary; one delta connected and the other wye connected. Each secondary winding is designed for operation with a three-phase, 6-pulse static power converter. Continuous operating voltage to ground is 2. 5 times rated line to line voltage.

唐钢用的是并行12脉冲而不是6脉冲驱动，变压器有三个绕组，一个用于一次侧（角接），两个用于二次侧，一个交接，一个星接。每个二次侧绕组被设计为三相六脉冲静态电力变频器。对地连续操作电压是额定线对线电压的２.５倍。

7.The corresponding terminals of the primary and secondary windings will be in

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