Multiphase light fixture
View Patent ↗Multiphase lighting fixtures having one or more light emitting diode (LED) light sources are provided. In one example implementation, a light fixture includes one or more light sources, such as LED light sources and a power conversion circuit. The power conversion circuit includes a phase shifting transformer for implementing a phase shift between output phases of secondary windings thereof, a multi-phase rectifier having a first rectifier and a second rectifier connected in parallel for converting a multiphase input power to a rectified output or a six-pulse configuration, a zero sequence blocking transformer for reducing harmonic distortion, an interphase transformer for further reducing harmonic distortion, and a current regulator for providing a constant DC current output to the one or more light sources. In some example implementations, the DC rectified output has a voltage ripple of less than about 7%, or less than about 3%.
1. A light fixture, comprising:
one or more light emitting diode (LED) light sources;
a power conversion circuit, the power conversion circuit configured to receive a multiphase input power comprising three or more alternating current phases and to convert the multiphase input power to a rectified output for powering the one or more LED light sources;
wherein the power conversion circuit comprises a multi-pulse, multiphase rectifier, the multi-pulse, multiphase rectifier having a first rectifier and a second rectifier coupled in parallel, the multi-pulse multiphase rectifier further having a zero sequence blocking transformer coupled to the first rectifier and the second rectifier, a phase shifting transformer having a primary winding, a first secondary winding and a second secondary winding, the first secondary winding coupled to the first rectifier, the second secondary winding coupled to the second rectifier, the multi-pulse multiphase rectifier further comprising an interphase transformer and a current regulator, wherein the current regulator is configured to receive the rectified output and provide a constant current to the one or more light emitting diode (LED) light sources.
2. The light fixture of claim 1 wherein the rectified output for powering the one or more light sources has a voltage ripple.
3. The light fixture of claim 2 , wherein the voltage ripple is less than about 7%.
4. The light fixture of claim 2 , wherein the voltage ripple is less than about 3%.
5. The light fixture of claim 2 , wherein a constant current from the current regulator is generated to power the one or more LED light sources such that the one or more LED light sources have a percent flicker of less than about 7%.
6. The light fixture of claim 2 , wherein a constant current from a current regulator is generated to power the one or more LED light sources such that the one or more LED light sources have a percent flicker of less than about 3%.
7. The light fixture of claim 1 , wherein the phase shifting transformer is configured to provide about a 30° phase shift between an output of the first secondary winding and the second secondary winding.
8. The light fixture of claim 1 , wherein the primary winding has a wye configuration, the first secondary winding has a wye configuration, and the second secondary winding has a delta configuration.
9. The light fixture of claim 1 , wherein the light fixture is a high-bay light fixture.
10. The light fixture of claim 1 , wherein the interphase transformer configured to provide a twenty-four pulse output.