Method for determining a motor type of an electric motor and motor control apparatus
AssigneeDanfoss Power Electronics A/S
InventorsAna-Mari Tataru Kjær, Sanjeet Kumar Dwivedi, Thiruvenkadam Madhulingam, Katuri Gudaru Venkaiah
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Abstract
A method for determining a motor type of an electric motor includes several phases, wherein two or more pulses are applied to the motor, respective currents are measured and the motor type is determined based on the pulses. Further, a motor control apparatus is configured to perform such a method.
Claims22
A method for determining a motor type of an electric motor having several phases and for controlling the motor using a motor control apparatus, the method comprising the following steps:
- applying two or more pulses to the electric motor, each pulse representing a vector with respect to the phases,
- measuring respective time-resolved currents while applying the pulses,
- analyzing at least some of the currents,
- determining the motor type based on the currents, and
- controlling the electric motor, using the motor control apparatus, as an Asynchronous Motor (ASM) when the saliency indicator is less than a first value,
- wherein analyzing the currents comprises determining a pulse with highest peak current and a pulse with lowest peak current, and
- wherein a saliency indicator is calculated as a ratio between the highest peak current and the lowest peak current.
A method for determining a motor type of an electric motor having several phases and for controlling the motor using a motor control apparatus, the method comprising the following steps:
- applying two or more pulses to the electric motor, each pulse representing a vector with respect to the phases,
- measuring respective time-resolved currents while applying the pulses,
- analyzing at least some of the currents, and
- determining the motor type based on the currents,
- controlling the electric motor using the motor control apparatus based on the determined motor type,
- wherein analyzing the currents comprises determining a pulse with lowest peak current and a pulse opposite thereto, and
- wherein analyzing the currents comprises determining a pulse with highest peak current and a pulse opposite thereto;
- and
- further comprising the following steps:
- fitting a respective function to the pulse with lowest peak current and to the pulse opposite thereto,
- wherein the function is a third order polynomial function for current y versus time x with coefficients a, b, c, and d:
- y=ax{circumflex over ( )}3+bx{circumflex over ( )}2+cx+d, and
- fitting a respective function to the pulse with highest peak current and to the pulse opposite thereto,
- wherein the function is a third order polynomial function for current y versus time x with coefficients a, b, c, and d:
- y=ax{circumflex over ( )}3+bx{circumflex over ( )}2+cx+d,
- wherein if a has negative sign, b has positive sign and c has positive sign for the pulse with lowest peak current and if a has negative sign, b has positive sign and c has positive sign for the pulse with highest peak current, then controlling the electric motor, using the motor control apparatus, as an Asynchronous Motor (ASM) or as a Synchronous Reluctance Motor (SRM).
Dependencies are inferred from the claim text.