Pre-charging an inverter using an auxiliary winding
AssigneeTECO-Westinghouse Motor Company
InventorsMehdi Abolhassani, Thomas Keister, Alex Skorcz, Ryan Edwards, Enrique Ledezma
Life of this patent
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Abstract
A transformer module includes a main primary winding coupled to a first input power source to receive a medium voltage signal, multiple main secondary windings each to couple to a power cell of a drive system, and an auxiliary primary winding coupled to a second input power source to receive a low voltage signal. The auxiliary primary winding can be spatially separated from the main windings to increase leakage inductance. The auxiliary primary winding can be active during a pre-charge operation to pre-charge the power cells.
Claims18
An apparatus comprising:
- a transformer module for a medium voltage drive, the transformer module including:
- a main primary winding coupled to a first input power source to receive a medium voltage signal therefrom;
- a plurality of main secondary windings each to couple to a power cell of the medium voltage drive;
- and
- an auxiliary primary winding coupled to a second input power source to receive a low voltage signal therefrom, wherein the auxiliary primary winding is spatially separated from the main primary winding and the plurality of main secondary windings;
- and
- a cabinet coupled to the transformer module to provide the medium voltage signal and the low voltage signal to the transformer module, wherein the cabinet includes a control circuit to provide the low voltage signal to the transformer module on power up of the medium voltage drive and after a predetermined time or a command signal to switch off the low voltage signal to provide the medium voltage signal to the medium voltage drive, wherein the control circuit is to switch the low voltage signal to the medium voltage drive when a loss of the medium voltage signal is detected during operation of the medium voltage drive.
A medium voltage drive system comprising:
- a transformer module switchably coupled to receive one of a low voltage signal and a medium voltage signal, and having a main primary winding coupled to receive the medium voltage signal, a plurality of main secondary windings each coupled to a power cell, and an auxiliary primary winding coupled to receive the low voltage signal, wherein the auxiliary primary winding is spatially separated from the main primary winding and the plurality of main secondary windings, the auxiliary primary winding to receive the low voltage signal during a pre-charge of the medium voltage drive system and during a power loss event, and otherwise the auxiliary primary winding is deactivated and the main primary winding is to receive the medium voltage signal.
A method comprising:
- switching a low voltage signal to an auxiliary primary winding of a modular transformer of a drive system having a main primary winding, a plurality of main secondary windings each coupled to a power cell, and the auxiliary primary winding, wherein the auxiliary primary winding is spatially separated from the main primary winding and the plurality of main secondary windings;
- unswitching the low voltage signal from the auxiliary primary winding and switching a medium voltage signal to the main primary winding of the modular transformer when a predetermined voltage level of a bus capacitance of a power cell coupled to the modular transformer has been reached;
- and
- detecting a loss of the medium voltage signal and switching the low voltage signal to the auxiliary primary winding of the modular transformer.
Dependencies are inferred from the claim text.