A phase inversion propeller-type tidal power generator whose size is 1/7 that of the actual generator (source: NEDO)
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New Energy and Industrial Technology Development Organization (NEDO), Kyowa Engineering Consultants Co Ltd (Kitakyushu City), Eim Electric Co Ltd, Maeda Corp, Kyushu Institute of Technology and Waseda University announced Nov 17, 2017, that they have developed a phase inversion propeller-type tidal power generation technology as an elemental technology of next-generation ocean energy power generation.

The six organizations conducted a towing test from Oct 17 to 20, 2017, and confirmed a power generation efficiency of 43.1%, which is higher than expected at the time of designing the generator.

They used a tidal power generator using the "phase inversion method," which rotates the outer coil and inner shaft magnet of the generator in opposite directions by using front and rear propellers. Because the relative speed of cutting a magnetic field increases, compared with the single row of propellers of the previous system, a higher power generation efficiency can be expected.

Also, the power generation voltage increases, making it possible to reduce power transmission loss, the capacity of power control equipment, etc. Furthermore, the rotation torque of the generator can be offset, eliminating the reaction to the outside and enabling to simplify the supporting structure.