In networked energy supply systems, surplus electrical energy from renewable sources is temporarily stored as chemical energy in the form of hydrogen. The hydrogen circuit enables hydrogen to be stored and, when needed, converted back into electrical energy. Doing so balances out any deviations between energy supply and demand.
The ET 278 trainer contains all the components needed to study the conversion of electrical energy into hydrogen and the reverse conversion back into electrical energy in a circuit. Hydrogen is produced from ultrapure water in an electrolyser. The proton exchange membrane (PEM) technology is used to break down water (H2O) into hydrogen (H2) and oxygen (O2). The required cell voltage is provided in the electrolyser via a DC voltage source.
The hydrogen produced is temporarily stored in a buffer tank after treatment. The stored hydrogen is then converted back into water in a fuel cell using PEM technology, together with oxygen from the ambient air. This produces electrical energy and closes the hydrogen circuit. The electrical energy is used to power a consumer (halogen lamp).
Measured values for hydrogen flow rate and pressure, as well as current and voltage at the electrolyser are monitored. An energy balance can be calculated from the recorded measured values.
The system is controlled via an integrated PLC with touch screen. The experimental plant can alternatively be operated and controlled via a terminal device by means of an integrated router. The user interface can also be displayed on other terminals (screen mirroring). The measured values can be stored internally via the PLC. It is possible to access stored measured values from terminals via WiFi using the integrated router/LAN connection to the customer’s own network.
