MJ2 Technologie sas products

Noting that on a number of applications the VLH turbines were not necessarily the best solution for the site, we decided to develop a range of Kaplan conventional turbines, with vertical double or single adjustment as well as horizontal or inclined axial turbines, which we exclusively propose equipped with PMGA direct  drive generators.

The VLH appears as an almost square-shaped self-supporting mechanically welded structure. It receives the guide vanes, as well as stiffeners. The assembly forms a grid where the spacing between bars is designed to prevent clogging up. The grid profiles ensure the mechanical hold of the bulb containing the generator and the turbine.

The central system controller defines the operating parameters of the turbine based on the head height measurements and other operating parameters, with the same principle as the logic controller used for conventional equipment.

The frequency converter of full output capacity gives the VLH the possibility to modify its rotation speed according to the operation conditions. It is formed of a power rectifier associated with a capacitor bank and an inverter providing a 50- or 60-Hz signal. This industrial equipment has been manufactured for more than ten years as a standardized line, with a modularity enabling to adapt its capacity to the installed power capacity of each VLH.

The permanent magnet variable-speed generator is directly coupled to the turbine. It has an external rotor. The stator windings are assembled on a fixed shaft in central position.

Hydraulic turbines are bulky by nature. Indeed, to generate even relatively moderate output (on the order of some hundred  kW) under heads lower than 3 m, turbine flow rates can exceed 10 m3/s. This results, for water supply works, in large civil engineering structures proportioned to the collected flow rates.

The VLH appears as an almost square-shaped self-supporting mechanically welded structure. It receives the guide vanes, as well as stiffeners. The assembly forms a grid where the spacing between bars is designed to prevent clogging up. The grid profiles ensure the mechanical hold of the bulb containing the generator and the turbine.

The permanent magnet variable-speed generator is directly coupled to the turbine. It has an external rotor. The stator windings are assembled on a fixed shaft in central position. They are ventilated and refrigerated by contact with the water flowing around the bulb and by fans. The rotor is equipped with permanent magnets, and is solid with the turbine runner. The magnets are assembled at the stator periphery.

The frequency converter of full output capacity gives the VLH the possibility to modify its rotation speed according to the operation conditions. It is formed of a power rectifier associated with a capacitor bank and an inverter providing a 50- or 60-Hz signal. This industrial equipment has been manufactured for more than ten years as a standardized line, with a modularity enabling to adapt its capacity to the installed power capacity of each VLH. The quality of the generated electric signal is such that ERDF (the French national electric utility) does not require installation of so-called “trap” circuits for this type of installation. Further, the system’s capacity of instantaneous regulation makes it particularly well adapted to an isolated network operation.