Abstract: Systems for controlling hydrogen purity in a power plant system are disclosed. In one embodiment, a hydrogen control system for a generator housing includes: a mass flow control system fluidly connected to the generator housing, the mass flow control system being configured to measure a flow rate of a gas mixture extracted from the generator housing and modify the flow rate of the gas mixture across a range of flow rates; and a vent conduit fluidly connected to the mass flow control system, the vent conduit for receiving a portion of the gas mixture from the mass flow control system and feeding the portion of the gas mixture to an outlet.

Abstract: A hydrogen cooled generator includes a lubricant drain system. The lubricant drain system includes a hydrogen detraining tank having a hollow interior portion. A sensor is operatively mounted in the hydrogen detraining tank. The sensor is configured and disposed to detect an interface zone between an amount of lubricant and an amount of hydrogen gas in the hollow interior portion. A drain line is fluidly coupled to the hydrogen detraining tank. The drain line includes a first end portion that is exposed in the hollow interior portion and a second end portion. A valve is mounted in the drain line. A controller is operatively connected to the sensor and the valve. The controller is configured to selectively open the valve allowing a portion of the amount of lubricant to flow from the hollow interior portion when the interface zone is above the first end portion of the drain line.