300MW機(jī)組DEH設(shè)計說明書

1、 1.工程概況Overview of project300MW機(jī)組系哈爾濱汽輪機(jī)有限責(zé)任公司設(shè)計生產(chǎn)的N300-16.7/538/538型亞臨界一次中間再熱、高中壓合缸單軸雙缸雙排汽凝汽式汽輪發(fā)電機(jī)組，系統(tǒng)為單元制熱力系統(tǒng)。300MW汽輪機(jī)采用高壓主汽門方式?jīng)_轉(zhuǎn)，轉(zhuǎn)速達(dá)到2900RPM時切換到高壓調(diào)門控制升速、帶負(fù)荷。每臺機(jī)組配有兩個高壓主汽門（TV）、六個高壓調(diào)門（GV）、兩個中壓主汽門（RSV）和兩個中壓調(diào)門（IV）。機(jī)組啟動運(yùn)行方式：定滑定運(yùn)行，高壓缸啟動負(fù)荷性質(zhì)：帶基本負(fù)荷，可調(diào)峰運(yùn)行周波變化范圍：48.550.5Hz旁路形式及容量：30B-MCR高低壓串聯(lián)簡易旁路機(jī)組額定出力：300

2、MW主汽閥前額定蒸汽壓力：16.7MPa（a）主汽閥前額定蒸汽溫度：538主汽門前蒸汽流量：889.87T/H中聯(lián)門前蒸汽壓力：3.228MPa（a）中聯(lián)門前蒸汽溫度：538中聯(lián)門前蒸汽流量：741.76T/H抽汽壓力： 0.2450.785Mpa額定背壓： 4.5kPa（a）機(jī)組工廠編號：73B300MW汽輪機(jī)調(diào)節(jié)系統(tǒng)為高壓抗燃油型數(shù)字電液調(diào)節(jié)系統(tǒng)（簡稱DEH），電子設(shè)備采用了上海西屋控制系統(tǒng)有限公司的OVATION系統(tǒng)，液壓系統(tǒng)采用了哈爾濱汽輪機(jī)廠有限責(zé)任公司成套的高壓抗燃油EH裝置。本說明書僅涉及DEH電氣部分，液壓部分請參考相關(guān)資料。The steam turbine, type N3

3、00-16.7/538/538, manufactured by HTC is tandem compound, single reheat, regenerative, double exhaust, condensing, multi-cylinder design with combined HP-IP and separate LP casing, 3000 rpm speed, directly coupled with Generator. One boiler feeding one steam turbine thermodynamic system is applied to

4、 the power plant. The steam turbine rolls up and accelerates controlled by throttle valves (i.e. TV control mode). At 2900 rpm, control of speed is transferred from the throttle valves (TV control mode) to the governor valves (GV control mode). Each unit is equipped with two throttle valves (TV), si

5、x governor valves (GV), two reheat stop valves (RSV) and two interceptor valves (IV). Start up and operation mode: be capable of start up on TV control mode and operation on constant pressure-sliding pressure-constant pressure mode.Load carrying: be capable of operation on rated load or on peaking l

6、oad service either.Tolerant frequency swing rang: 48.550.5 HZ.Bypass configuration and size: 30%-MCR HP and LP simplified bypass in series.Rated load: 300MWRated inlet steam pressure of main stop valve (MSV, i.e. TV): 16.7MPa (a)Rated inlet steam temperature of main stop valve: 538 Inlet steam flow

7、of main stop valve: 889.87 T/HExtraction steam pressure: 0.2450.785MPaInlet steam pressure of reheat stop valve (RSV): 3.228MPa (a)Inlet steam temperature of main stop valve: 538 Inlet steam flow of reheat stop valve: 741.76 T/HRated back pressure: 4.5kPa (a)Turbine serial number: 73BDigital electro

8、-hydraulic control system (DEH) equipped with high pressure fire-resistant fluid system is applied to 300MW turbine. Ovation system supplied by shanghai Westinghouse is used for DEH system as hardware. EH fluid system is designed and supplied by HTC.This system design description (SDD) concerns DEH

9、system only. EH fluid system refers to relevant documents.2.系統(tǒng)配置及組成DEH system configuration and modulesDEH控制系統(tǒng)均采用了上海西屋控制系統(tǒng)有限公司的OVATION系統(tǒng)。DEH由兩個控制柜(DPU41/91、DPU42/92);一個繼電器柜;一套Ovation 工程師/高性能工具庫工作站；一套Ovation操作員工作站組成。Ovation控制器建立在開放的工業(yè)標(biāo)準(zhǔn)基礎(chǔ)之上，是最有效的工業(yè)過程控制器。由于在系統(tǒng)心臟配有英特爾奔騰處理器，Ovation 控制器能使發(fā)展極為迅速的微處理技術(shù)容易地結(jié)

10、合進(jìn)系統(tǒng)中。Ovation控制器執(zhí)行簡單或復(fù)雜地調(diào)節(jié)和順序控制策略，能實現(xiàn)數(shù)據(jù)獲取功能，可以與網(wǎng)絡(luò)及I/O子系統(tǒng)連接。標(biāo)準(zhǔn)化地PC 結(jié)構(gòu)和無源的PCI/ISA總線接口使控制器可以與其他標(biāo)準(zhǔn)PC產(chǎn)品的即插即用操作、運(yùn)行相兼容。高性能的Ovation工作站工作環(huán)境為帶有Solaris操作系統(tǒng)的SUN 工作站。工程師站、操作員站均采用該平臺。Ovation 工程師/高性能工具庫工作站提供現(xiàn)代化過程控制系統(tǒng)所要求的可靠性、高性能和靈活性，基于WIONDOWS 或UNIX的Ovation 工程師/高性能工具庫工作站與Ovation 網(wǎng)絡(luò)完全匹配，最大容量可達(dá)點。正常操作遵循Ovation安全系統(tǒng)規(guī)則。O

11、vation 工程師/高性能工具庫服務(wù)器將所有工程師功能綜合到一個單獨的工作站內(nèi)。它包括：l 系統(tǒng)軟件服務(wù)器l 高性能工具數(shù)據(jù)庫l 高性能工具庫l 操作員功能l 各種工程師功能等與Ovation 工程師/高性能工具庫工作站相同，Ovation 操作員工作站也是基于WIONDOWS 或UNIX的工作站，并與Ovation 網(wǎng)絡(luò)完全匹配，最大容量可達(dá)點。正常操作同樣遵循Ovation安全系統(tǒng)規(guī)則。Ovation 操作員工作站對控制圖形、診斷、趨勢、報警和工廠狀態(tài)顯示提供一個高分別率的窗口。用戶通過操作員工作站可訪問動態(tài)系統(tǒng)測點及歷史數(shù)據(jù)、綜合信息、標(biāo)準(zhǔn)功能顯示、事件記錄和復(fù)雜報警管理程序。操作員工

12、作站通過高速網(wǎng)絡(luò)提供準(zhǔn)確、連續(xù)的過程信息。Ovation操作員工作站具有以下功能：l 過程圖監(jiān)視與操作l 報警管理l 趨勢顯示l 測點信息/測點檢查l 操作員事件報告The DEH system for this project is an Ovation based Distributed Control System (DCS). DEH system is furnished with software package and hardware. DEH system consists of two redundant Ovation controllers, two cabinets

13、used for Ovation controllers, one relay extension cabinet, one Ovation Engineer/Power Tools workstation and one operator workstation.Based on open industry standards, the Ovation Controller is the industrys most powerful process controller. With an Intel Pentium PC at its heart, the Ovation Controll

14、er allows rapidly advancing microprocessor technology to be easily integrated into the system. The Ovation controller executes simple or complex modulating and sequential strategies, performs data acquisition functions, and interfaces to the Ovation Network and I/O subsystem. Standard PC architectur

15、e and passive PCI/ISA bus interface makes the Controller compatible for plug-and-play operation with other standard PC products. Ovation Workstations are available in Windows-based and UNIX based Sun Solaris versions, offering an unprecedented level of performance. These platforms can serve as eithe

16、r operator or engineer workstations. The Ovation workstations offer our customers the stability, power, and flexibility they need to operate their process control systems of modernization. Windows-based or UNIX-based Ovation Engineer/Power Tools workstations are fully compatible with the Ovation net

17、work with access up to 200,000 points. General operation is conducted under limits defined in the Ovation security system. The Ovation Engineer/Power Tools server combines all Engineer functionality into a single workstation. Following software severs and power tools are included:l System software s

18、erverl Power tools databasel Power toolsl Operator functionsl All engineer functionalitySame with the Ovation Engineer/Power Tools workstation, WINDOWS-based or UNIX-based Ovation operator workstations are fully compatible with the Ovation network with access up to 200,000 points. General operation

19、is conducted under limits defined in the Ovation security system either. Ovations operator workstation provides a high resolution window to the process through control graphics, diagnostics, trending, alarms and plant status displays. The Ovation operator workstation provides access of dynamic syste

20、m points, displays historical data, general messages, logs process events, and monitors plant operations through a sophisticated alarm management system. The Ovation operator workstation communicates via a high speed network, providing accurate, continuous process information. Standard operator work

21、station functions are as follows:l Process Diagram Systeml Alarm Managementl Trendingl Point Informationl Point Reviewl Operator Event Messaging2.1模件Ovation I/O modulesDEH一共配置了33塊模件，這些模件安裝在DPU41/91、DPU42/92機(jī)柜內(nèi)。電子模塊特性模塊數(shù)量名稱用途1C31194G011C31197G0110閥定位模塊控制電液伺服閥1C31189G011C31192G013速度檢測器模塊轉(zhuǎn)速測量1C31234G01

22、1C31238H013數(shù)字量輸入模塊開關(guān)量輸入1C31122G011C31125G022數(shù)字量輸出模塊開關(guān)量輸出5X00058G015X00059G014模擬量輸入模塊（HART）模擬量輸入（420mA）1C31129G031C31132G012模擬量輸出模塊模擬量輸出（420mA）5X00119G015X00121G014熱電阻輸入模塊溫度信號輸入（RTD）5X00070G041C31116G045熱電偶輸入模塊溫度信號輸入（TC）The DEH system is equipped with 32 modules totally mounted in the cabinets of DPU

23、41/91 and DPU42/92. 2.1.1閥定位模塊 Valve Positioner ModuleOvation閥定位I/O模塊提供汽輪機(jī)可調(diào)蒸汽閥門閉環(huán)位置控制。I/O模塊為電液伺服閥執(zhí)行器和Ovation控制器之間的接口。主汽閥、高壓調(diào)節(jié)閥及再熱調(diào)節(jié)閥均由閥定位模塊控制。它實際上是一塊智能I/O模件，通過其上的處理器完成蒸汽閥門的精確定位控制。閥定位模塊可以設(shè)定閥的位置設(shè)定值，通常這是Ovation控制器來完成的。在模塊內(nèi)部，微處理器提供實時閥位的閉環(huán)PI(比例積分)控制，閥位設(shè)定值引起I/O模塊產(chǎn)生冗余輸出控制信號，這些控制信號驅(qū)動電液伺服閥執(zhí)行器上的線圈，和安裝在閥桿上的LV

24、DT而檢測到的閥位信號一起構(gòu)成閉環(huán)回路。每塊控制一個可調(diào)蒸汽閥門（modulated steam valve），因此DEH配置了10閥定位模塊：TV2、GV6、IV2。The Ovation Valve Positioner I/O module provides closed loop position control of a steam turbine valve. The I/O module serves as the interface between the Ovation Controller and an electro-hydraulic servo valve actua

25、tor. Valve styles controlled by this module include throttle, governor and interceptor. The Ovation Valve Positioner I/O module is a smart module. Precise position control is implemented by built-in micro-controller. The Ovation Valve Positioner module maintains a valve position set point, normally

26、determined by the Ovation Controller. Within the module, the micro-controller provides closed loop proportional-plus-integral (PI) control for real time valve position control. The Valve position set point causes the I/O module to generate redundant output control signals. These output signals drive

27、 the electro-hydraulic servo valve actuators coils. The feedback loop is closed with the valves position measurement which is obtained from an LVDT mounted on the valve stem. One Valve Positioner module controls one modulated steam valve and thereby, ten Valve Positioner modules are supplied for one

28、 steam turbine according to the layout of servo valve actuators (Viz. TVX2, GVX6, IVX2). 速度檢測器模塊Speed Detector ModuleOvation速度檢測器I/O模塊通過檢測安裝在汽輪機(jī)前箱內(nèi)磁阻式轉(zhuǎn)速探頭輸出信號的頻率而得到汽輪機(jī)的轉(zhuǎn)速。它將磁阻式轉(zhuǎn)速探頭輸出信號的頻率轉(zhuǎn)換成16bit 和32 bit二進(jìn)制數(shù)，16 bit輸出值，以5ms速度更新信息，用來檢測汽輪機(jī)的轉(zhuǎn)速。32 bit輸出值，也以適當(dāng)?shù)乃俣雀聰?shù)據(jù)，控制汽輪機(jī)的轉(zhuǎn)速。速度檢測器模塊由一個現(xiàn)場卡和一個邏輯卡組成。現(xiàn)場卡內(nèi)有一個

29、信號處理電路，用來讀取轉(zhuǎn)速探頭送來的脈沖輸入信號。在轉(zhuǎn)速探頭和邏輯卡信號之間采用光電耦合器連接使信號之間電子隔離?，F(xiàn)場卡內(nèi)的電路可以檢測在低阻抗源（小于5000歐姆）時回路的開路狀態(tài)。邏輯卡提供所有的邏輯功能，包括將從現(xiàn)場卡接收的轉(zhuǎn)速信號轉(zhuǎn)換成Ovation系統(tǒng)可以讀入的16bit 或32 bit信號。每塊接受一路轉(zhuǎn)速脈沖信號，因此DEH配置了三塊轉(zhuǎn)速測量模件。The Ovation Speed Detector I/O module determines the speed of turbine by the frequency of the magnetic speed pickup ou

30、tput signal. It converts magnetic speed pickup output frequency into 16 bit and 32 bit binary numbers. The 16 bit output, updated at a rate of 5ms detects turbine over speed and the 32 bit output, updated at a variable rate, regulates turbine speed.The Speed Detector module consists of a field card

31、and a logic card. The field card contains signal conditioning circuitry for reading magnetic speed pickup signals, which can be sinusoidal or pulse train inputs. Opto coupler are used to provide electrical isolation between the magnetic speed pickup and logic card signals circuitry is provided withi

32、n the field card to detect open wire conditions for low resistance source, less than 5000 Ohms.The logic card provides all function logic, which converts magnetic speed pickup signals received from the field card to either 16 or 32 bit signals that can be read by the Ovation system. One Speed Detect

33、or I/O module receives one way pulse signal and thereby, three Speed Detector I/O modules are supplied for one steam turbine according to the layout of speed detectors. 2.1.3數(shù)字量輸入模塊Ovation數(shù)字量輸入系統(tǒng)帶有電子模塊和相應(yīng)的特性模塊。特性：數(shù)字量輸入模塊的通道為16路開關(guān)量（干接點）查詢電壓為48VDC2.1.4數(shù)字量輸出模塊特性：為16路開關(guān)量輸出子模塊2.1.5模擬量輸入模塊（帶有HART功能） 特性：為8

34、路模擬量輸入模塊，專門用于420mA或15VDC模擬量輸入測量通過不同的接線方式，可實現(xiàn)電流輸入方式（外部提供24VDC）或者變送器輸入方式（機(jī)柜內(nèi)部提供24VDC）。2.1.6模擬量輸出模塊 特性：為4路模擬量輸出模塊，專門用于420mA信號輸出2.1.7熱電阻輸入模塊 特性：為8路熱電阻輸入模塊，專門用于熱電阻（RTD）溫度信號測量。2.1.8熱電偶輸入模塊 特性：為8路熱電偶輸入模塊，專門用于熱電偶（TC）溫度信號測量。Digital Input ModuleFeatures:The Ovation Digital Input System is furnished with elect

35、ronics module and corresponding personality module. 16 individually isolated inputs (un-wetted contact) for per digital input module 48VDC wetting power supplyDigital Output ModuleFeatures:16 individually isolated outputs for per digital output moduleAnalog Input Module（HART）Features:8 individually

36、isolated inputs for per analog input moduleInput range 4 to 20mA and 1to 5VDC are both available for analog output moduleField powered current input connections (external 24VDC) and locally powered input connections (internal 24VDC) can be conducted under different connection methodsAnalog Output Mo

37、duleFeatures:16 individually isolated outputs for per analog output module Output range 4 to 20mA is available only for analog output moduleRTD Input ModuleFeatures:8 individually isolated inputs for per RTD input module used for resistance temperature signal detecting only Thermal couple Input Modu

38、leFeatures:8 individually isolated inputs for per thermal couple input module used for thermal couple signal detecting only3. 系統(tǒng)設(shè)計原則l 系統(tǒng)符合“故障-安全”設(shè)計準(zhǔn)則，當(dāng)系統(tǒng)失電時保證可靠停機(jī)，并對可能的誤操作應(yīng)采取有效的防范措施。l 系統(tǒng)具有自診斷、自恢復(fù)和抗干擾能力。l 控制系統(tǒng)依據(jù)分層、分散控制原則，除了控制器冗余外，對重要的I/O信號和I/O模件也進(jìn)行冗余配置。l 冗余的高速通訊網(wǎng)絡(luò)保證信息通暢，并具有與DCS的通訊接口。l 除滿足機(jī)組啟動運(yùn)行控制要求外，

39、系統(tǒng)具有足夠的I/O裕量和能力以便未來進(jìn)行功能擴(kuò)展。l 硬件選擇力求可靠、先進(jìn)。l 功能設(shè)計應(yīng)符合標(biāo)準(zhǔn)化、通用化、模塊化的原則。l 操作站設(shè)計符合人機(jī)工程學(xué)要求，人機(jī)界面友好，信息豐富，操作簡便可靠。System design principlesl In compliance with fail safe rule, the system should provide effective provisions for conceivable mal-operation and ensures a safe shutdown of the turbine against system powe

40、r lost. l Abilities of self-diagnosis, self-recovery and anti-interferencel As per the rule of hierarchical structure control and distributed control, In addition to the controller, configuration of those vital I/O signals is redundant either. l Redundant fast communication network provides uninterr

41、upted flow of process data and offers communication interfaces with DCS.l In addition to meeting the requirements of normal start up and operation control, the system should be capable of being expanded with enough I/O margin.l Keep pursuing reliability and advance of hardware selectionl Function de

42、sign should be in compliance with standardization, generalization and modularizationl Operator workstation design should be in compliance with requirements of man machine engineering， offering friendly man machine interface, abundant messages, reliable and easy handling.4. DEH控制功能Digital Electro-Hyd

43、raulic Control System Functions DEH主要控制汽輪機(jī)轉(zhuǎn)速和功率。通過控制TV、GV、IV和RSV，能夠?qū)崿F(xiàn)從汽機(jī)盤車、掛閘、沖轉(zhuǎn)、暖機(jī)、進(jìn)汽閥切換、同期并網(wǎng)、帶初負(fù)荷到帶全負(fù)荷的全程自動控制。同時，具備防止汽機(jī)超速的保護(hù)邏輯。DEH控制功能分別由兩對冗余的控制器實現(xiàn)，即基本控制和自啟停（包括轉(zhuǎn)子應(yīng)力計算）。The Digital Electro-Hydraulic Control System (DEH) performs two main functions: control of turbine speed, and control of turbine l

44、oad. The turbine is brought up to rated load automatically through the control procedures of rolling off turning gear, latching the turbine, rolling up, heat soaking, TV/GV transferring, synchronizing and initial load loading by opening throttle valves, governor valves, reheat strop valve and interc

45、eptor valves. Meanwhile, protection logic against turbine overspeed is also provided. Two redundant controllers are offered to DEH system.4.1超速保護(hù)部分Overspeed Protection Control (OPC)超速保護(hù)部分的主要作用是提供轉(zhuǎn)速三選二、油開關(guān)狀態(tài)及汽機(jī)自動停機(jī)掛閘（ASL）狀態(tài)三選二、超速保護(hù)邏輯、超速試驗選擇邏輯以及DEH跳閘邏輯，它控制著OPC電磁閥，同時匯總DEH相關(guān)跳閘信號后通過硬接線送ETS。 Overspeed Pro

46、tection Control provides 2 out of 3 voting logics to vital inputs such as the turbine speed, generator breaker and auto stop latch (ASL). In addition, overspeed protection logic, overspeed test logic and DEH trip logic are offered either. It controls OPC solenoids and sends summarized DEH appropriat

47、e ection logic, overspeed test and DEH trip logico trip signals by hardwire to ETS simultaneously.4.1.1系統(tǒng)轉(zhuǎn)速選擇Turbine Speed Selection轉(zhuǎn)速三選二實際上是三取中邏輯，如圖4.1所示。該邏輯容許在三個信號中的兩個相等的情況下，確保信號的精確測量。即當(dāng)一個信號失效的情況發(fā)生時，算法塊取剩余兩個有效信號的平均值，同時發(fā)出報警信號告知操作員出現(xiàn)了失效或不可靠的測點。2 out of 3 voting logic of turbine speed is median signa

48、l selection actually, shown in Figure 4-1. This smart logic ensures accurate signal measurement by requiring at least two of the three inputs to equal one another within a configurable tolerance. This logic becomes particularly useful when one of the three inputs fails. In this instance, the algorit

49、hm calculates the average of the remaining two good signals and an alarm is triggered to inform the operator of the failed or unreliable input.圖4.1三選二邏輯Median Signal Selection Logic當(dāng)出現(xiàn)以下情況時認(rèn)為系統(tǒng)轉(zhuǎn)速信號故障：l 任意兩路轉(zhuǎn)速故障l 一路轉(zhuǎn)速故障，另外兩路轉(zhuǎn)速偏差大l 三路轉(zhuǎn)速互不相同發(fā)生系統(tǒng)轉(zhuǎn)速故障后，在未并網(wǎng)的情況下DEH將停機(jī)信號送ETS。Under following conditions, the

50、 selected speed is set in failure:1. When there are any two speed pickups in failure.2. When there is one speed pickups in failure, and there is a control deviation alarm between the two speed pickups.3. When all three speed pickups are in control deviation with each other.If any of abovementioned c

51、onditions occurs and the unit is not synchronized, DEH should trip the turbine via ETS.4.1.2油開關(guān)狀態(tài) Generator breaker StatusDEH判斷機(jī)組是否并網(wǎng)的唯一根據(jù)是油開關(guān)狀態(tài)，因此該信號的重要性不言而喻。因此，DEH程序?qū)祥l信號采取三取二邏輯來可靠地判別機(jī)組狀態(tài)?；谕瑯拥脑?，DEH判斷汽機(jī)是否掛閘也是通過對AST母管壓力的三取二實現(xiàn)的。Generator breaker status is the most important and exclusive signal use

52、d for identifying whether the unit is synchronized or not. 2 out of 3 voting logic is applied to the three generator breaker status signals to ensure the reliable acknowledgement of the unit situation. Based on same reason, applying the same logic to auto stop trip (AST) header pressure signals to i

53、dentify whether the turbine is latched or not.4.1.3超速保護(hù)Overspeed Protection Control Function 超速保護(hù)（OPC）通過控制OPC電磁閥快速關(guān)閉GV和IV，有效防止汽輪機(jī)轉(zhuǎn)速飛升，并將轉(zhuǎn)速維持在3000RPM。它實際上由兩部分組成：并網(wǎng)前轉(zhuǎn)速大于103保護(hù)和并網(wǎng)后甩負(fù)荷預(yù)感器（LDA）。并網(wǎng)前以下條件引起OPC保護(hù)動作：l 未進(jìn)行電氣超速或者機(jī)械超速試驗轉(zhuǎn)速超過3090RPM發(fā)電機(jī)解列瞬間如果中壓缸排汽壓力（IEP）大于額定值的30或者該測點發(fā)生故障，則無論此時轉(zhuǎn)速是否超過3090RPM，OPC電磁閥都要動

54、作2秒，甩負(fù)荷預(yù)感器在延遲時間結(jié)束而且轉(zhuǎn)速小于103時將復(fù)位。When the turbine speed exceeds 103 percent of rated speed or loses the complete load, Overspeed Protection Control (OPC) closes governor valves and interceptor valves rapidly by energizing the OPC solenoids to prevent the turbine from speed overshooting effectively. Ov

55、erspeed Protection Control (OPC) is achieved by the Overspeed function (turbine speed exceeds 103 percenet of rated speed, prior to synchronizing) and the Load Drop Anticipator of overspeed-complete loss of load function (LDA).Prior to synchronizing, OPC solenoids are energized caused by following c

56、onditions:l With the turbine off-line, the turbine speed exceeds 3090rpm, without electrical overspeed test or mechanical overspeed test in progressAt the moment of generator breaker opens, LDA is set requesting OPC action. All governor and interceptor valves are then rapidly closed when the IP exha

57、ust pressure (IEP) is greater than 30 percent of rated pressure or the IEP signal is failed, the LDA function will hold the Governor and Intercept valves closed for a time delay (2 seconds) regardless of whether the turbine speed exceeds 3090rpm or not. The Load Drop Anticipator reset is determined by the speed being less than 103 percent and an elapsed time 4.1.4DEH跳閘 DEH Trip Function300MW汽輪機(jī)跳閘功能是由ETS控制AST電磁閥實現(xiàn)了，DEH只匯總以下的跳閘條件并將其送往ETS系統(tǒng)：l 并網(wǎng)前系統(tǒng)轉(zhuǎn)速故障或者超速（大于3300RPM）l 控制器故障(包含DEH失電)DEH summarizes following trip signals a