Drive equipment and control method
AssigneeTMEIC Corporation
InventorsMostafa Mamun, Akihiko Kuroiwa
Life of this patent
Estimating the term…
Abstract
A drive equipment includes a transformer, a power converter, and a control system. The transformer is configured with a primary winding and a secondary winding, and a winding of an electric motor is connected to the secondary winding. The power converter causes a current to flow through the primary winding of the transformer. The control system performs constant current control on the power converter during a period of a first stage after startup of the electric motor is instructed, to reduce a variation in a current flowing through the primary winding of the transformer, and controls the power converter through variable voltage variable frequency control of the electric motor in a second stage after the first stage.
Claims10
A drive equipment comprising:
- a transformer configured with a primary winding and a secondary winding, an electric motor being connected to the secondary winding;
- a power converter configured to cause a current to flow through the primary winding of the transformer;
- and
- a control system configured to perform constant current control on the power converter so that a current at a predetermined desired frequency flows from the power converter to the primary winding of the transformer during a period of a first stage after startup of the electric motor is instructed, to reduce a variation in a current flowing through the primary winding of the transformer, and to control the power converter through variable voltage variable frequency control of the electric motor in a second stage after the first stage,
- wherein the control system controls a frequency of the current caused to flow by the power converter so that a frequency component having a frequency higher than a frequency determined in advance in the desired frequency is included in a current flowing the primary winding of the transformer to demagnetize the transformer.
A control method for a drive equipment including a transformer configured with a primary winding and a secondary winding, a winding of an electric motor being connected to the secondary winding, and a power converter configured to cause a current to flow through the primary winding of the transformer, the control method comprising:
- performing constant current control on the power converter so that a current at a predetermined desired frequency flows from the power converter to the primary winding of the transformer during a period of a first stage related to startup of the electric motor to reduce a variation in the current flowing through the primary winding of the transformer;
- controlling the power converter through variable voltage variable frequency control of the electric motor in a second stage after the first stage;
- and
- controlling a frequency of the current caused to flow by the power converter so that a frequency component having a frequency higher than a frequency determined in advance in the desired frequency is included in a current flowing the primary winding of the transformer to demagnetize the transformer.
A drive equipment comprising:
- a transformer including a primary winding and a secondary winding, an electric motor being connected to the secondary winding;
- a power converter configured to cause a current to flow through the primary winding of the transformer;
- and
- a control system configured to perform constant current control on the power converter so that a current at a predetermined desired frequency flows from the power converter to the primary winding of the transformer during a period of a first stage after startup of the electric motor is instructed, to reduce a variation in a current flowing through the primary winding of the transformer, and to control the power converter through variable voltage variable frequency control of the electric motor in a second stage after the first stage;
- wherein the control system decreases, over time, the current flowing through the primary winding of the transformer during the period of the first stage, and decreases, over time, a frequency of the current flowing through the primary winding of the transformer as the desired frequency during the period of the first stage.
Dependencies are inferred from the claim text.