Control stability in closed volume systems is essential in many applications including cell research and fuel cell testing. Managing oscillation loops in dual valve systems is a critical part of enabling precision control of these systems. This led us to develop our controller deadband functionality.
Balancing the operation of an inlet valve and an exhaust valve allows the PCD series to perform precise and extremely fast closed system pressure control, while minimizing the waste of potentially expensive gases. At the core of our ability to do this is a well-balanced PD2I algorithm. But when changing conditions, like ambient temperature, affect the system, active control can over compensate and cause oscillation loops.
Controller deadband functionality on our dual valve control systems allow users to create a +/- band of change around their chosen setpoint. So once a system has successfully attained setpoint, if ambient conditions cause slight variances to the held value, the controller will not respond with a valve change, until the user defined “deadband” around the controller is exceeded. Adding a depth of stable control to an already fast and dynamic control algorithm.
With these improvements our dual valve pressure controllers still provide the same speed you’ve come to know from our mass flow controllers with the added benefit of maintaining stability in fluctuating systems.