Abstract:
The invention relates to a circuit arrangement and a method for operating an electric motor in a direct voltage source, in particular for operating a permanent-magnet-excited DC motor in the direct voltage network of a motor vehicle, having a rotary position transducer (32) for detecting the rotary position of the rotor (20), and having an electronic commutation controller (32) for switching over the current in the armature winding of the stator (12) as a function of the position of the rotor (20). It is proposed that the rotary position transducer (32) is positioned relative to the stator (12) for an early commutation, and that the actual commutation time can be set by means of a delay correction, ascertained by measurement separately for each motor (10), in the electronic commutation controller (30).
Abstract:
A method and system for determining the commutation position in a DC machine using a single-bit rotor sensor and the back EMF signal from a stator winding by calculating a delay value, which is equal to the time elapsed between detection of the position signal and the back EMF signal, and establishing commutation after a period of time equal to the delay value has elapsed from when the position signal is detected.
Abstract:
A control circuit is described in which a single input terminal receives digital control signals and analog control signals. In accordance with the principles of the invention, the control circuit includes an automatic power down circuit to place the control circuit into a low power draw or “sleep” mode whenever predetermined conditions are present. The automatic power down circuit monitors the single input terminal and when no demand for motor operation occurs for a predetermined period of time, the automatic power down circuit operates to place the control circuit into the low power draw mode.
Abstract:
A controller with attachments for controlling specific electronic circuits is disclosed. Each attachment has a connector connectable to the electronic circuit to be controlled, and a memory accessible by the controller that contains configuration data for accessing the electronic circuit, and operational software for operating the electronic circuit.
Abstract:
An electronically commutated motor has a rotor (108), a stator having a stator winding arrangement (102), and a full bridge circuit (137) for controlling the current (i1, i2) in the stator winding arrangement (102); in the full bridge circuit (137), first semiconductor switches (114, 130) are connected to a first DC supply lead (116) and second semiconductor switches (132, 136) to the other DC supply lead (122), said second switches being bidirectionally conductive of current in the switched-on state. The motor has an arrangement (172, 198, 188) for opening the first semiconductor switches (114, 130) and for closing the second semiconductor switches (132, 136) during a predetermined operating state. An arrangement (202) is provided for monitoring the direction of the current (i1, i2) which flows in the second semiconductor switches (132, 136) when the latter are conductive during the predetermined operating state.
Abstract:
Below a predetermined threshold value of the rotation speed, a sinusoidal or trapezoidal current is applied to the winding sections of a brushless DC motor. Above the predetermined threshold value of the rotation speed, the brushless DC motor is operated with block commutation. The brushless DC motor thus produces a very uniform torque over a very wide operating range, and can at the same time be designed to be very compact.
Abstract:
A motor control system for a two-phase brushless DC motor uses measured EMF voltage from the passive set of stator coils to control commutation. A microcontroller receives the EMF voltage measurement and compares it to a threshold voltage value, which may be speed-dependent for advance commutation at high motor speeds. A match of the EMF voltage measurement with the threshold value triggers commutation of the drive to the opposite set of stator coils. The microcontroller also has an up-down counter timer whose count value is compared to an external speed reference. Each match of the count value triggers a transition in a pulse-width modulated (PWM) drive signal. The duty cycle of the PWM signal establishes an average drive voltage that controls motor speed.
Abstract:
A control system for a motor including a rotor comprises a sensorless sensor module that includes a saliency-based estimator module that generates a first rotor position signal based on saliency and a back electromotive force (emf) estimator module that generates a second rotor position signal based on back emf. A selector selects the first rotor position signal for rotor speeds below a first rotor speed and the second rotor position signal for rotor speeds above the first rotor speed. A rotor position sensor senses a position of the rotor and generates a third rotor position signal. A fault detection module senses faults in the rotor position sensor and outputs the third rotor position signal when a fault is not detected and one of the first and second rotor position signals when the fault is detected. An indirect field oriented control (IFOC) system controls the motor based on a selected one of the first, second and third rotor position signals.