A method is for a network synchronization of a permanently excited three-phase machine including a soft starter, including thyristors, and mechanical bypass contacts for bridging the thyristors in the network operation. The method includes generating a first control signal, to initiate switching the mechanical bypass contacts to become conductive, after a criterion is reached while running up the three-phase machine on the soft starter, a time at which the first control signal is generated representing actuation time of the bypass contacts; generating ignition pulses for the thyristors within a time period, running from the actuation time to a contact time of the bypass contacts, using a second control signal; and operating the three-phase machine in the network operation via the bypass contacts. Each ignition pulse for a thyristor is generated when a phase current measurement indicates that the current strength in the assigned phase has fallen below a threshold value.

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.

According to one embodiment, a driving device includes a voltage controller, a parameter setter, and a phase adjuster. The voltage controller causes an electric power converter to apply a drive voltage to the electric motor, the electric power converter converting input electric power to A/C electric power having desired voltage and frequency and supplying the converted electric power to an electric motor. The parameter setter sets at least one of a rotation speed of the electric motor and a parameter related to the rotation speed as speed information. The phase adjuster adjusts a phase of the drive voltage in such a manner that an index calculated based on a current flowing in the electric motor and the speed information set in the parameter setter becomes smaller.

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.

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.

A motor control device includes processing circuitry configured to calculate a current command value corresponding to torque that should be generated by a motor, divide the calculated current command value into individual current command values for coil groups, control power feeding to the coil groups independently for each of the coil groups based on a corresponding one of the individual current command values, set, for each one of the coil groups, an upper limit value of a corresponding one of the individual current command values and, when the individual current command value for any one of the coil groups is limited to a value that is smaller than a corresponding one of the upper limit values, supplement an amount limited in the individual current command value by increasing the individual current command value for at least a remaining one of the coil groups.

A thyristor starter accelerates a synchronous machine from a stop state to a predetermined rotation speed by sequentially performing a first mode of performing commutation of an inverter by intermittently setting DC output current of a converter to zero and a second mode of performing commutation of the inverter by induced voltage of the synchronous machine. In the thyristor starter, during a first time period from start of performance of the second mode to arrival of the induced voltage of the synchronous machine at a first voltage value, a phase control angle of the inverter is changed such that a value thereof becomes larger as a rotation speed of the synchronous machine becomes higher.

A thyristor starter accelerates a synchronous machine from a stop state to a predetermined rotation speed by sequentially performing a first mode of performing commutation of an inverter by intermittently setting DC output current of a converter to zero and a second mode of performing commutation of the inverter by induced voltage of the synchronous machine. In the thyristor starter, during a first time period from start of performance of the second mode to arrival of the induced voltage of the synchronous machine at a first voltage value, a phase control angle of the inverter is changed such that a value thereof becomes larger as a rotation speed of the synchronous machine becomes higher.

This motor control device controls a motor having a first stator winding, a second stator winding, and a field winding whose response to a current command is slower than those of the first stator winding and the second stator winding, and includes: a parameter acquisition unit which acquires motor state data and a motor parameter corresponding to the motor state data; and a current command calculation unit which calculates current commands for the windings on the basis of a torque command for the motor and the motor parameter. The current command calculation unit includes a response delay reproduction unit which reproduces response delay of field winding current in a field winding current command, and calculates a first stator winding current command and a second stator winding current command, using the field winding current command in which the response delay is reproduced.

This motor control device controls a motor having a first stator winding, a second stator winding, and a field winding whose response to a current command is slower than those of the first stator winding and the second stator winding, and includes: a parameter acquisition unit which acquires motor state data and a motor parameter corresponding to the motor state data; and a current command calculation unit which calculates current commands for the windings on the basis of a torque command for the motor and the motor parameter. The current command calculation unit includes a response delay reproduction unit which reproduces response delay of field winding current in a field winding current command, and calculates a first stator winding current command and a second stator winding current command, using the field winding current command in which the response delay is reproduced.