The present invention relates to the technical field of
electrolysis cell control. Disclosed are a method and
system for controlling a separator liquid level during
hydrogen production by water
electrolysis. In the present invention, the separator liquid level is used as a primary variable, and the make-up
water flow rate is used as a secondary variable, forming a
cascade control system. In addition, the change values of an
electrolysis system pressure, electrolysis
cell power, and an alkaline solution temperature are used as feed-forward signals and are respectively input into feed-forward controllers. Output values are summed and then used, together with the
cascade control system, to form a feed-forward-
cascade control system. The control method can achieve precise control of the liquid level on a
hydrogen side and the liquid level on an
oxygen side, thereby avoiding the problem of an excessive difference in liquid level between the
hydrogen side and the
oxygen side caused by changes in the
system pressure, the electrolysis
cell power, the alkaline solution temperature, and the make-up
water flow rate, avoiding the problem of equipment damage and even personal injuries resulting from the risk of explosion due to mixing of gases on two sides when the liquid levels are too low, and avoiding economic losses caused by protective shutdown triggered by high or low liquid level alarms.