A high-efficiency motor control system and method is presented for controlling an electric motor. The system can feature a multi-phase inverter having a logic control device and associated control circuity, a plurality of floating charge pumps and pump circuitry, a multi-phase bridge having a plurality of power switching devices and a bootstrap capacitor circuit having a floating ground. The floating charge pumps feature grounds electrically coupled to motor phase leads. The bootstrap circuit can feature a floating ground, with a floating voltage being carried across the bootstrap circuit and delivered to the switching devices to produce an indefinite on-time for the switching devices for switching the high-side of a power supply to a load.

A closed-loop system may include a plant (an elctric machine requiring control) and a fractional-order proportional-resonant controller. The fractional-order proportional-resonant controller may have an order greater than zero and less than or equal to one. The order for the fractional-order proportional-resonant controller may be selected to yield a target amplitude and target slope for frequency response. The frequency response may be such that a steady-state error associated with a speed of the electric machine is inversely proportional to the target amplitude and less than a predetermined threshold. The order of the controller may be 0.9.

A system and method for limiting the vibration of an electric motor so as to avoid situations in which extreme vibration may result in damage to the motor or other equipment. A motor control subsystem runs the motor in accordance with a command specifying a speed or torque. A vibration sensor, such as a three-axis accelerometer, senses a vibration of the electric motor, or, alternatively, software indirectly detects the vibration based on phase or torque ripple. Such vibration may be caused by, e.g., a broken fan blade or an accumulation of snow or ice. A control element receives data regarding the vibration, determines whether the vibration exceeds a pre-determined limit, and if so, takes action to reduce the vibration of the electric motor below the pre-determined limit. Such action may involve slowing or stopping the motor, thereby avoiding damage, increasing reliability, and reducing cost.

According to one embodiment, a motor drive control device includes a PWM control circuit that generates PWM signals corresponding to a predetermined exciting current pattern, an H bridge circuit that is constituted of switch transistors whose on/off is controlled by the PWM signals, a coil to which an exciting current is supplied from the H bridge circuit, and a current detection circuit that detects a current flowing into the coil. A value of a parameter of the exciting current pattern is corrected by using the detection result of the current detection circuit.

A system to detect a ground fault at the output of an inverter section prior to powering up a motor drive system is disclosed. A low voltage power supply is connected to the DC bus prior to connecting the input power source to the rectifier section. If a ground fault exists, the voltage potential on the DC bus causes conduction through one of the freewheeling diodes connected in parallel to the power switching device on the output of the inverter section. A fault detection circuit generates a signal corresponding to the presence of the low voltage potential when the low voltage is applied to the DC bus. If a ground fault is present at the output of one of the inverter sections, the motor drive system prevents the AC voltage from being applied to the rectifier section.

The present invention relates to a method for use in dynamometer testing of a vehicle (100), the vehicle (100) including at least a first wheel shaft and at least one first vehicle power source for providing power to said first wheel shaft, said first wheel shaft being connected to a vehicle dynamometer system, said vehicle dynamometer system comprising a first controllable dynamometer power source (201) for providing power to said first wheel shaft, said first dynamometer power source being an electrical machine (201) comprising a stator and a rotor, said stator comprising a stator winding. The method includes: determining whether a first temperature (T.sub.1) is below a first temperature limit (T.sub.lim1), and heating said electrical machine (201) by applying a current (I.sub.heat) to said stator winding when said first temperature (T.sub.1) is below said first temperature limit (T.sub.lim1).

A variable frequency motor drive comprises a converter including a rectifier having an input for connection to an AC power source and converting the AC power to DC power. A DC bus is connected to the rectifier circuit. At least one bus capacitor is across the DC bus. An inverter receives DC power from the DC bus and converts the DC power to AC power to drive a motor. A controller is operatively connected to the converter. The controller comprises a speed control controlling the inverter responsive to a speed command to maintain a desired motor speed. A speed foldback control measures DC bus ripple voltage and regulates the speed command responsive to the measured DC bus ripple voltage.

A device including: a command-generator outputting a drive command signal to a drive unit; a detector outputting a position-detection signal of the drive unit; a drive-current detector outputting a drive-current detection value; a controller receiving the drive command and position-detection signals to generate a drive-force command signal, and supplying the drive current according to the drive-force command signal and the drive-current detection value; a friction-characteristics-estimator receiving a drive force signal and the position-detection signal to output a friction-characteristics estimate value; a temperature-information acquirer outputting a temperature information value; a friction modeling unit having a set reference friction model having temperature-dependent characteristics, and outputting reference friction characteristics based on the temperature information value; and a friction-variation analyzer outputting a friction variation value based on variation of the friction-characteristics estimate value from the reference friction characteristics.

A safety system has higher user design flexibility. Motor controllers (20, 30) include a motor drive circuit (207) that outputs a motor voltage command signal for driving motors (90, 100) in accordance with a motor drive command value, an inverter (211) that supplies power for driving the motors (90, 100) by switching based on the motor voltage command signal, a safety control unit that outputs a drive permission signal for driving the motors (90, 100) in accordance with communication data received through a communication circuit (213), a cut-off circuit (209) that receives the drive permission signal and the voltage drive command signal and cuts off the voltage drive command signal to an inverter (211) when receiving no drive permission signal, and a safety input unit (205) that receives redundant safety input signals. The cut-off circuit (207) receives a logical AND of the safety input signal and the drive permission signal.

A method and an assembly for pivoting a movable component having a drive device with an electric drive motor in order to influence a pivoting of the component between a first setting and a second setting. A position sensor detects a position measure for a setting of the component and a speed parameter for a displacement speed of the component. During a displacement of the component with the speed parameter, an electrical setpoint current intensity for the electric drive motor is ascertained, and an associated setpoint voltage is set. The setpoint voltage is increased if a current intensity flowing through the drive motor is lower than the electrical setpoint current intensity, and the setpoint voltage is reduced if the current intensity flowing through the drive motor is higher than the electrical setpoint current intensity.