Rolls-Royce Corporation

Nanyang Technological University

King Jet Tseng

Ellis F H Chong

Shanmukha Ramakrishna

Boon Hee Soong

Szu-Cheng Chien

Yee Loon Sum

Kin Hey Chu

A synchronous electrical machine includes a stator having a circumferential row of teeth carrying stator windings. The electrical machine further includes a coaxial rotor having a circumferential row of poles carrying field windings. Each pole has first and second side flanks and a tip surface which extends continuously there between to form an air gap to the teeth of the stator. On a transverse cross-section through the machine, one of the side flanks forms a leading edge of the pole, and the other side flank forms an opposite, trailing edge of the pole. Each pole carries a row of permanent magnets which extends across the tip surface from one of the side flanks to the other side flank, the permanent magnets compensating for armature magnetic reaction. The radial thickness of the permanent magnets increases smoothly with progressive distance across the tip surface from one of the side flanks to the other side flank.

Electrical machine

Various embodiments provide a method of controlling a lighting device to generate light of a desired natural scene. The lighting device may include a plurality of warm white LEDs having a first intensity range and a plurality of cool white LEDs having a second intensity range. The method may include dividing each of the first intensity range and the second intensity range into a predetermined number of intensity levels; initializing the plurality of warm white LEDs to a first intensity level and initializing the plurality of cool white LEDs to a second intensity level, the first intensity level and the second intensity level being determined based on the desired natural scene; iteratively adjusting at least one of the intensity level of the warm white LEDs or the intensity level of the cool white LEDs by at least one level in each iteration, until the light generated by the lighting device matches a desired correlated color temperature predetermined for the desired natural scene; and iteratively adjusting at least one of the intensity level of the warm white LEDs or the intensity level of the cool white LEDs, until the light generated by the lighting device matches a desired illuminance predetermined for the desired natural scene.

Lighting control method and system

Growing community of inventors

Singapore, Singapore

King Jet Tseng