A method for controlling a three-level brake chopper and a three-level brake chopper including, a first controllable semiconductor switch connected between a positive direct current pole and a first connection point, a second controllable semiconductor switch connected between the first connection point and a neutral direct current pole, a third controllable semiconductor switch connected between the neutral direct current pole and a second connection point, a fourth controllable semiconductor switch connected between the second connection point and a negative direct current pole, resistance means connected between the first connection point and the second connection point, and control means configured to control the second controllable semiconductor switch and the third controllable semiconductor switch into a conducting state in response to detecting a fault in the resistance means.

A motor driver for driving a single coil motor, the motor driver includes: a bridge driver configured for applying a driving signal to the single coil by commuting a motor voltage (Vmot) or a motor current (Imot), supplied to the bridge driver, between terminals (OUT1, OUT2) of the single coil; a controller configured for controlling the commuting of the bridge driver and for setting a preferred value of the motor voltage in function of a preferred operating point; a first voltage regulator configured for regulating the motor voltage or the motor current to the preferred value.

A motor control device includes a motor drive circuit including an upper arm and a lower arm, an arithmetic processor to control the motor drive circuit, an alternative circuit that can operate as a substitute to replace the arithmetic processor, and a mode switch to switch a control mode between a first control mode, in which the arithmetic processor controls the motor drive circuit, and a second control mode, in which the alternative circuit controls the motor drive circuit, based on a state of the arithmetic processor. The mode switch switches the control mode from the first control mode to the second control mode when a state of the arithmetic processor changes from a normal state to an abnormal state.

A motor unit comprises a power supply, a diode, a capacitor, and a motor controller, where the motor controller comprises a switch unit and a control unit. The switch circuit includes a first upper-side switch, a first lower-side switch, a second upper-side switch, and a second lower-side switch. The control unit is configured to turn on the first upper-side switch and the second lower-side switch and turn off the first lower-side switch and the second upper-side switch. When an input voltage is less than a first reference voltage, the control unit is configured to turn off the first upper-side switch and the second lower-side switch. The motor controller may be configured to avoid an overvoltage problem.

A bridge circuit includes a high-side transistor connected between a power supply terminal and an output terminal, and a low-side transistor connected between the output terminal and a ground terminal. A high-side pre-driver and a low-side pre-driver drive the high-side transistor and the low-side transistor. A first transistor is connected between the output terminal and the ground terminal in a manner to form the regenerative path parallel to the low-side transistor. In a regenerative state in which a current sinks from the output terminal, a regenerative control circuit controls the voltage of a control terminal of the first transistor in a manner that an output voltage of the output terminal approaches a target voltage higher than the power supply voltage of the power supply terminal by a first voltage width.

A circuit for a multi phase bridge inverter having a plurality of high and low side switches arranged to be coupled, respectively, to first and second power source busbars. The multi phase inverter is arranged to control current flow in coil windings of an electric motor, and a DC link capacitor is coupled between the first and second power source busbars. The circuit comprises first and second impedances coupled in series between the first and second power source busbars and in parallel to the DC link capacitor, and means coupled between the first and second impedances for providing a voltage from the coupling between the first and second impedances to the low side switches upon the occurrence of a first predetermined condition to place the low side switches in a close circuit configuration to allow coil windings of an electric motor to be placed in a short circuit configuration.

A motor protecting circuit is provided. A first terminal of each of high-side transistors is coupled to a power supply voltage. A second terminal of each of low-side transistors is grounded. Second terminals of the high-side transistors are respectively connected to first terminals of the low-side transistors. An overvoltage detector circuit is coupled to the power supply voltage of an output circuit. When the overvoltage detector circuit determines that the power supply voltage of the output circuit is higher than a voltage threshold, the overvoltage detector circuit outputs an overvoltage detected signal to a controller circuit. According to the overvoltage detected signal, the controller circuit controls a driver circuit to turn on at least one of the high-side transistors and at least one of the low-side transistors at the same time.

A motor controller includes a rectifier module, an inverter circuit, an energy storage capacitor C1, a DC inductor L1, a microprocessor, and a lightning protection and surge protection circuit. The rectifier module includes an output end connected to the energy storage capacitor C1 to charge the energy storage capacitor C1; two ends of the energy storage capacitor C1 are connected to the inverter circuit to supply power to the energy storage capacitor C1. The DC inductor L1 is in series connection between a positive output end A of the rectifier module and a positive end B of the energy storage capacitor C1. The lightning protection and surge protection circuit is disposed between the rectifier module and the energy storage capacitor C1. The lightning protection and surge protection circuit includes a differential mode protection circuit and a primary common mode protection circuit.

The invention relates to a method for checking an electrical value of an electric machine, in particular an electric machine of a coordinate measuring device. The electric machine has an electric drive comprising a stator and a rotor. The method includes the steps of: detecting a value of a drive current delivered to the electric drive for driving the rotor, detecting a measured value of an electrical input variable of the electric machine, determining a calculated value of the electrical input variable on the basis of the detected value of the drive current and on the basis of a performance model of the electric machine, and determining a comparison value on the basis of the detected measured value and the calculated value of the electrical input variable, in order to check the detected value of the drive current.

A method for controlling a power converter of a wind turbine power system connected to an electrical grid. The wind turbine power system has a generator and the power converter has rotor-side converter and a line-side converter. The method includes monitoring an electrical parameter of at least one of the wind turbine power system or the electrical grid. In response to detecting a transient event in the electrical grid, the method includes temporarily disabling the line-side converter of the power converter from the electrical grid. Either during the transient event or after the transient event is over, the method includes implementing a control action for the line-side converter of the power converter. Further, the method includes enabling the line-side converter of the power converter to the electrical grid.