电压源型电力推进变频器抵御电网波动的应用研究

Study on Electrical Propulsion Frequency Converter of Voltage Source against Power Grid Fluctuation

电压源型变频器的直流母线电压取决于输入电压,当输入电压激烈波动时,母线电压也会剧烈波动,甚至引起变频器故障跳闸。当配电板母线发生短路故障时,系统电压降往往很大,在故障配电板被切除前,变频器面临欠压故障跳闸的风险。目前,要求多段配电板合成一段进行动力定位操作的应用越来越多,一段配电板的电网,短路电流比分段运行时大,故障造成的电压波动将传递到整个电网和在网设备,如果推进变频器及其辅机不能承受瞬时的电网剧烈波动,那么变频器将故障跳闸。由于推进变频器跳闸不能在短时间内恢复运行,这将使全船面临失去定位能力的风险。为了使推进变频器能承受瞬时电压降,需要使用变频器自带"抗扰"功能。经分析"抗扰"功能的原理,并在实船海试过程中验证变频器"抗扰"功能的可靠性。

The DC bus voltage of voltage source frequency converter depends on the input voltage. When the input voltage has violent fluctuation, the bus voltage will follow suit, and even cause trip failure of the frequency converter. When short circuit failure occurs to the switchboard bus, the system voltage will drop significantly. Therefore, the frequency converter is facing the risk of trip failure before the faulty switchboard is cut out. Nowadays, there is a growing demand for the combination of several switchboards into one bus-tie to perform the dynamic positioning operation. The short circuit current in bus-tie power grid is larger than that of a separate switchboard, and the voltage fluctuation caused by failure will transmit to the whole power grid and equipment within. If the propulsion frequency converter and its auxiliary machine cannot bear the transient violent fluctuation, a trip will happen. As the propulsion frequency converter cannot be resumed in a short time, the whole ship will face the risk of losing dynamic positioning capacity. In order to enable the propulsion frequency converter to bear a transient voltage drop, it is necessary to let the frequency converter to have its own ＂anti-disturbance＂ function. The reliability of the ＂anti-disturbance＂ function is validated through the analysis of the principle of＂anti-disturbance＂ and the sea trial.