摘要:
A motor control system includes a control module, a switching module, and a filtering module. The control module determines output voltages for operating a motor based on a torque demand. The switching module generates switching signals for an inverter that drives the motor. The switching module generates the switching signals based on the output voltages. The switching module generates an out-of-volts (OOV) signal according to a comparison based on the output voltages, a maximum duty cycle, and a voltage of a direct current (DC) bus that provides power to the inverter. The filtering module generates an OOV amount by filtering the OOV signal. The control module selectively limits the torque demand based on the OOV amount.
摘要:
Systems and methods for controlling a rotating electromagnetic machine. The rotating machine, such as a permanent magnet motor or hybrid switched reluctance motor, includes a stator having a plurality of phase windings and a rotor that rotates relative to the stator. A drive is connected to the phase windings for energizing the windings. A controller outputs a control signal to the drive in response to inputs of demanded torque, rotor position and/or speed. Control methods include calculating a scaled torque demand from the received torque demand to obtain substantially constant torque over a range of motor speeds, calculating an optimal dr-axis injection current using a cost function and a starting method that switches from speed control mode to torque control mode at a predetermined rotor speed or at predetermined start-up timing intervals.
摘要:
Systems and methods for controlling a rotating electromagnetic machine. The rotating machine, such as a permanent magnet motor or hybrid switched reluctance motor, includes a stator having a plurality of phase windings and a rotor that rotates relative to the stator. A drive is connected to the phase windings for energizing the windings. A controller outputs a control signal to the drive in response to an input demand such as a demanded speed or torque. Control methods (which can be implemented separately or in combination) include varying the gain of an estimator as a function of a demanded or estimated speed to position control system poles at desired locations, decoupling control system currents to achieve a constant torque with motor speed, compensating flux estimates of the estimator for saturation operation of the stator, estimating rotor position using averages of sample values of energization feedback, and calculating a trim adjusted speed error from a plurality of speed estimates.
摘要:
A force control system for an electromagnetic actuator includes an observer that outputs signals representing the instantaneous position and velocity of a movable member, and a position controller that receives the output of the observer and signals representing a desired position and a desired velocity. The position controller compares the output of the observer with the desired position and velocity signals to generate position and velocity error signals. The position controller further generates force command signals required to position the movable member at the desired position with the desired velocity based on the position and velocity error signals. The position component may be eliminated from the force command signals, resulting in controlling only the velocity of the movable member. In accordance with other aspects of the invention, a force control system for an electromagnetic actuator includes a flux observer that low-pass filters the voltage applied to phase coils to estimate the flux of the phase coil and provide a signal representing the estimated flux at the output.
摘要:
A system for controlling the movement of a movable member with respect to a stationary member, such as is found in a vibration welding apparatus. The system may include a force controller that converts desired force command signals into desired flux command signals and a flux controller that controls the flux in a magnetic core of the stationary assembly to effect the desired movement of the movable member. The stationary assembly may include a plurality of magnetically uncoupled E-cores of paramagnetic material.
摘要:
A digital power factor correction circuit including a digital comparator that compares the actual DC bus voltage of an electric circuit with a desired DC bus voltage to produce a digital attenuation signal in the form of a pulse width modulated signal that is used to attenuate the voltage from a time-varying source. The attenuated source voltage is used as the current demand signal for a current controller that controls the current drawn from the line.
摘要:
An improved EMI filter design is provided for an inverter operated dynamoelectric machine. A lossy balun wound choke is connected between a power supply in the form of a bridge rectifier and the inverter. The choke acts as a source resistance. Using the choke as the source resistance, an equiripple approximation to linear phase filter is derived. The filter is placed on the input side of the bridge rectifier. A method of designing an EMI filter for use in conjunction with an inverter operated dynamoelectric machine.
摘要:
A BPM or SRM electric motor (M) is supplied bus current. A PWM inverter (I) uses bus current to commutate the motor by Systematically energizing and de-energizing the motor's windings (W) with the current. The resultant bus current waveshape has characteristics that are a function of a commutation angle between a rotor (T) of the machine and its windings. The waveshape includes the effects of bus ripple or transients. A commutation controller (10) samples the waveshape during each commutation interval to obtain commutation angle information. The controller provides control inputs to an inverter (I) to control commutation angle in response to the sample information. Commutation angle control includes calculating a control variable (I.sub.curve) which is a function of commutation angle. This variable is comprised of sampled data values which are additively combined according to a prescribed formula and which provide a high degree of linearity over a wide range of commutation angles. The controller is further responsive to the motor's impulse response (H.sub.motor (t)) to reject bus ripple effects on the waveshape samples. By employing the control variable and impulse response, the controller provides appropriate frequency (f.sub.out) and voltage (V.sub. out corrected) inputs to the inverter to achieve an optimum commutation angle relationship between the rotor and windings.
摘要:
A system includes a pulse-width modulation (PWM) module, a subtraction module, an error reducing module, and a summing module. The PWM module controls switching of an inverter that powers a motor. The PWM module controls the switching based on a first angle in a first mode and a second angle in a second mode. The subtraction module determines a difference between the first and second angles. The error reducing module (i) stores the difference when a transition from the first mode to the second mode is commanded and (ii) decreases a magnitude of the stored difference to zero. The summing module calculates a sum of the stored difference and the second angle. The PWM module controls the switching based on the sum in the second mode.
摘要:
Various methods of detecting a found rotor, a lost rotor, a locked rotor and a caught rotor after a power disruption using flux estimates are disclosed. Also disclosed are permanent magnet motor controllers and assemblies suitable for performing one or more of these methods.