Objective to control end prevent the occupational hazards in the workplaces 摘要目的預(yù)防、控制和消除作業(yè)場(chǎng)所職業(yè)病危害。
From no control before july 1988 we acquired indirect control july 1988 and subsequently direct control end - 1996 我們由對(duì)總結(jié)馀沒有控制權(quán)1988年7月以前,到取得間接控制權(quán)1988年7月,以至取得直接控制權(quán)1996年底。
A non - linear feed - forward loop is used to realize the coordinated control between the two controlled variables at the two control ends at first . secondly , a constant ac voltage control is implemented for a short period after the ac fault removal . finally , a staggered recovery strategy for different hvdc subsystems is also adopted , with the restart time interval of them optimized using the steepest descent gradient search method 該協(xié)調(diào)恢復(fù)策略的三個(gè)特點(diǎn)是:在常規(guī)的控制器結(jié)構(gòu)中加入一個(gè)基于準(zhǔn)穩(wěn)態(tài)工作點(diǎn)的非線性前饋回路;在交流故障被切除后的一個(gè)短暫時(shí)間內(nèi),逆變側(cè)采用定交流電壓控制:對(duì)不同的直流輸電子系統(tǒng)采取一種漸進(jìn)的恢復(fù)策略。