A power transmission apparatus, which is disposed on a power transmission path from an output shaft of an internal combustion engine to a transmission in a vehicle, is provided with a rotating electrical machine including a rotor and a stator. The rotor is coupled to a synchronous rotating member that rotates synchronously with the output shaft of the internal combustion engine, and takes a central axis of the output shaft of the internal combustion engine as a rotating shaft. The stator is fixed to a fixing member on a non-rotating side with respect to the synchronous rotating member, and faces the rotor with a first gap therebetween.

A circuit includes phase windings, a direct current (DC) power supply, and a power switch circuit. The power switch circuit includes at least one power switch. The circuit also includes a control circuit to control the power switch circuit. The control circuit includes a logic control shut off circuit to shut off the control circuit when the motor is at synchronous speed. The circuit also includes at least one non-collapsing DC power supply component to prevent the DC power supply from collapsing when the at least one power switch is on and conducting during at least a portion of a cycle. One or more of the DC power supply and power switch circuit may be at a midpoint of the phase windings.

Disclosed therein is a method of operating a variable magnetic flux motor. The method of operating the variable magnetic flux motor, which includes a rotor and a stator located inside the rotor, the rotor including first magnets and second magnets having a coercive force weaker than that of the first magnets, includes: a first step of operating the motor in an initially magnetized state of the second magnets; and a second step of operating the motor in an inversedly magnetized state of the second magnets by applying a magnetomotive force to the second magnets in the opposite direction to the magnetization direction of the second magnets.

Disclosed therein is a method of operating a variable magnetic flux motor. The method of operating the variable magnetic flux motor, which includes a rotor and a stator located inside the rotor, the rotor including first magnets and second magnets having a coercive force weaker than that of the first magnets, includes: a first step of operating the motor in an initially magnetized state of the second magnets; and a second step of operating the motor in an inversedly magnetized state of the second magnets by applying a magnetomotive force to the second magnets in the opposite direction to the magnetization direction of the second magnets.

A circuit element includes an upper switching device, a lower switching device, an upper diode device, and a lower diode device. An upper drain is connected to a first terminal connected to a positive electrode of a power supply, and an upper source is connected to a third terminal. A lower drain is connected to a fourth terminal, and a lower source is connected to a second terminal connected to a negative electrode of the power supply. An upper anode is connected to the fourth terminal, and an upper cathode is connected to the first terminal. A lower anode is connected to the second terminal, and a lower cathode is connected to the third terminal. The third terminal and the fourth terminal are arranged so as to be able to be short-circuited outside of a package.

This invention is concerning a controller for an AC rotating machine, this controller having an estimated sum current computing unit configured to output, as estimated sum current, a sum of current of a first winding and current of a second winding when it is determined that the current of the first winding can be detected, and maintain the estimated sum current which has been outputted as a previous value when it is determined that the current of the first winding cannot be detected. When it is determined that the current of the first winding cannot be detected, a first voltage command for the first winding is computed based on an estimated current value of the first winding, which has been calculated by subtracting the current of the second winding detected by the second current detector, from the estimated sum current output from the estimated sum current computing unit.

A method for sensorless control of a separately excited synchronous machine having a rotor includes the following steps: feeding a test signal on a parameter of an electrical current driving the rotor; measuring the parameter of the electrical current driving the rotor on an axis of the coordinate system describing the synchronous machine; determining an error signal by correlating the measured parameter of the electrical current driving the rotor with a temporally delayed test signal which is determined from the fed test signal; and adjusting a rotor angle as a reaction to the error signal if the error signal has a value not equal to zero.

A method for sensorless control of a separately excited synchronous machine having a rotor includes the following steps: feeding a test signal on a parameter of an electrical current driving the rotor; measuring the parameter of the electrical current driving the rotor on an axis of the coordinate system describing the synchronous machine; determining an error signal by correlating the measured parameter of the electrical current driving the rotor with a temporally delayed test signal which is determined from the fed test signal; and adjusting a rotor angle as a reaction to the error signal if the error signal has a value not equal to zero.

A parameterless and position-sensorless MTPA control of a permanent magnet synchronous motor including: using three rotating reference frames having different observation angles to parse the current vector; using a target current value and a preset current-rotor angle y that is between the current vector and the q.sub.r-axis of the (d.sub.r, q.sub.r) rotor reference frame to obtain the angles between the current vector, the voltage vector, and the rotor position; obtaining the target voltage value and the target voltage angle by using the obtained angles to obtain the target phase voltage values for regulation. The method is simple in controlling the motor, improves the control efficiency and reliability, and improves the control accuracy.

A parameterless and position-sensorless MTPA control of a permanent magnet synchronous motor including: using three rotating reference frames having different observation angles to parse the current vector; using a target current value and a preset current-rotor angle y that is between the current vector and the q.sub.r-axis of the (d.sub.r, q.sub.r) rotor reference frame to obtain the angles between the current vector, the voltage vector, and the rotor position; obtaining the target voltage value and the target voltage angle by using the obtained angles to obtain the target phase voltage values for regulation. The method is simple in controlling the motor, improves the control efficiency and reliability, and improves the control accuracy.