121 results about "Motor constants" patented technology

A method of measuring a motor constant is provided in a vector control apparatus for an induction motor. A voltage output phase [theta]v is set at an previously set arbitrary phase. Prior to applying a current, a current command is fed to operate the vector control apparatus with a proportional-plus-integral controller being set operative. After conduction for a predetermined time, the gain of the proportional-plus-integral controller is set to zero to maintain an integrated value constant and accordingly fix a voltage command value. In this state, a current command value and a detected current value are measured. k is measured at two levels of current, and a primary resistance value (or a line-to-line resistance value) is derived from the slope.

A motor control device includes a magnetization control unit energizing a motor winding to change magnetic flux content of permanent magnet motor, a current detector detecting current supplied to the motor, a vector control unit including a speed / position estimation unit carrying out an operation to estimate a motor rotational speed and rotational position, the vector control unit carrying out a vector control of the motor, an induced voltage detector detecting an induced voltage of the motor based on the rotational speed, motor currents obtained by the vector control unit, output voltages of the drive unit, a winding inductance or the motor constant and a winding resistance, an induced voltage command determining unit determining an induced voltage command based on the motor rotational speed and output torque, and a magnetization current determining unit determining an amount of energization based on the induced voltage of the motor and the induced voltage command.

A vector control system for a permanent magnet synchronous motor, using a current control equivalent output value, a frequency instruction value, a current detection value, an inference phase error value, and a motor constant, identifies a motor resistance equivalent or a resistance setting error equivalent. Next, the vector control unit, using the identified value, corrects a set value R* equivalent of a voltage instruction calculation unit and a n inference phase error calculation unit.Thereby, a vector control system for a permanent magnet synchronous motor can realize a robust control characteristic for changing of a resistance constant of a motor in a low rotation speed area under position sensor-less control. Further, a vector control system for a permanent magnet synchronous motor can be applied in common in a system performing inexpensive current detection.

An electric motor control device includes: a motor constant generator configured to generate a motor constant by using a temperature as a parameter; a current control unit configured to generate a current command value to an electric motor based on the motor constant and a torque command value and execute a current control mode in which a voltage applied to the electric motor is controlled to match the current command value; a voltage phase control unit configured to calculate a torque estimation value of the electric motor and execute a voltage phase control mode in which a feedback operation is performed for a voltage phase based on the difference between the torque estimation value and the torque command value; and a control mode switching unit configured to switch to the voltage phase control mode in a high rotation area where a flux weakening control is performed. The torque estimation value is calculated using the motor constant common to generation of the current command value in the current control mode.

The invention discloses a motor constant-speed forward / reverse rotation control circuit. A control signal output pin of a master chip outputs motor forward / reverse rotation control signals to the base electrode of a third crystal triode, the collector electrode of the third crystal triode is connected with a power source by an electromagnetic relay, and the electromagnetic relay is provided with at least a first moving contact and a second moving contact which are correspondingly communicated with the positive pole and the negative pole of the motor; the normally closed contact of the electromagnetic relay corresponding to the first moving contact is connected with the collector electrode of a first crystal triode, and the corresponding normally open contact is earthed; the normally closed contact of the electromagnetic relay corresponding to the second moving contact is earthed, and the corresponding normally open contact is connected with the collector electrode of the first crystal triode; and the base electrode of the first crystal triode is connected with the collector electrode of a second crystal triode, and a modulation signal output pin of the master chip outputs PWM signals to the base electrode of the second crystal triode. By controlling the electromagnetic relay based on the motor forward / reverse rotation control signals to realize the forward / reverse rotation of the motor and determining the rotation speed of the motor based on PWM signals, the invention has the advantages of high stability and low failure rate.