基于功角稳定的余热发电机励磁DSP控制系统

DSP control system of waste heat generator excitation based on power angle stability

余热发电较普通火力发电具有蒸气压力易突变的特点,现在国内余热发电机励磁并网后多采用恒功率因数调节方式。当汽轮机蒸气压力突变瞬间,由于有功功率同向突变,发电机的功角也同向变化,当功角超过允许值时,发电机有可能失步停车。针对此问题开发了基于DSP的励磁三闭环控制系统。当蒸气压力大于最大值时,发电机工作于恒功角方式。当蒸气压力小于最大值时,发电机工作于恒功率因数方式。并网前发电机工作于恒励磁电流方式,从而保证了发电机始终处于既节能又可靠的运行状态。

Compared with coal-fired power generation, steam pressure of waste heat power generation has the characteristic of mutation. Now the domestic waste heat generator excitation uses constant power factor regulating mode after connected with power grid. When steam pressure of steam turbine mutates, due to that active power mutation at the same direction, the gener ator power angle will change at the same direction too. When power-angle is more than the allowable value, generator may be out-of-step parking. Three closed loop excitation control devices based on DSP is developed to solve this problem. When the steam pressure is greater than the maximum value, generator works at constant power angle. When the steam pressure is less than maximum value, generator works at constant power factor mode. Before connected with power grid, generator works at constant exciting current mode, so that the generator is always energy-saving and in reliable operation.