作者:王雷,張麒(上海外高橋第三發(fā)電有限責(zé)任公司,上海 200137)
摘要:某火電廠原有集中式變頻供電系統(tǒng)為一批大型輔機(jī)提供集中調(diào)速電源。由于該供電系統(tǒng)為獨(dú)立微電網(wǎng),為維持系統(tǒng)頻率穩(wěn)定性及滿(mǎn)足輔機(jī)變頻運(yùn)行需要,汽輪機(jī)的調(diào)節(jié)閥門(mén)長(zhǎng)期處于節(jié)流狀態(tài),尤其是中低負(fù)荷區(qū)間時(shí)輔機(jī)變頻運(yùn)行所需功率相對(duì)汽輪機(jī)下降得更快,加劇了節(jié)流損失。本文介紹的新型電能轉(zhuǎn)換技術(shù)屬跨界集成創(chuàng)新,基于現(xiàn)有電力電子變頻技術(shù)和產(chǎn)品,在現(xiàn)有集中變頻供電系統(tǒng)與工頻系統(tǒng)之間,研發(fā)并增設(shè)一套新型電能轉(zhuǎn)換系統(tǒng),實(shí)現(xiàn)了集中式變頻供電系統(tǒng)與廠用電工頻系統(tǒng)兩個(gè)異頻電網(wǎng)之間的聯(lián)絡(luò)運(yùn)行,將集中變頻供電系統(tǒng)變化的電壓、頻率經(jīng)轉(zhuǎn)換后,輸出為可運(yùn)行于現(xiàn)有工頻系統(tǒng)的交流電源,并將集中變頻供電系統(tǒng)的富裕功率送至現(xiàn)有工頻系統(tǒng)。通過(guò)調(diào)節(jié)新型電能轉(zhuǎn)換系統(tǒng)的輸出功率,基本代替汽輪機(jī)調(diào)節(jié)閥門(mén)的調(diào)速功能,而且使汽輪機(jī)調(diào)門(mén)接近全開(kāi),減小節(jié)流損失、提高機(jī)組性能。
關(guān)鍵詞:電能轉(zhuǎn)換;異頻電網(wǎng)互聯(lián);集中變頻;反向電調(diào)門(mén)
Abstract: A centralized variable frequency power system has been built in a power plant to supply common electric power of speed governing operation for a number of large motors. However,the system forms a microgrid which frequency is different from utility power grid, so the turbine regulating valves often operate in throttling state,which not only provide the speed required by motors, but also keep the turbine speed stable.This means a lot of throttling loss, especially when the lower speed need of motors. The paper introduces a new technology of electric power transform based on the existing IGBT technology and product, which a new electric power transform system is developed and applied. The new system is an integrated innovation, successfully interconnects centralized variable frequency power system with utility power grid, converts varying voltage and frequency to nominal voltage and frequency, and transfer spare energy due to turbine valves almost fully open from centralized variable frequency power system to utility power grid. In addition to greatly reducing throttling loss, by adjusting the output power of the new system instead of turbine valves, like a backward acting regulating valve of electric, the system speed can be controlled well. The new system improves the performance of power plant unit.
Key words: Electric power transform; Interconnection between power grids with different frequency;Centralized variable frequency power system;Backward acting electric regulating valve
在線預(yù)覽:一種新型電能轉(zhuǎn)換技術(shù)及其應(yīng)用
摘自《自動(dòng)化博覽》2019年11月刊