The invention relates to a method for operating an electric machine (100) having a stator having stator windings and a rotor, having a converter (110) and having a sensor (120) for detecting a measurement value, wherein the converter (110) has direct current connections, alternating current connections and semiconductor switches for connecting one of the direct current connections to one of the alternating current connections in each case, wherein the stator windings are connected to the alternating current connections, the semiconductor switches of the converter (110) being closed and opened at specific changeover times, a measurement being carried out by the sensor (120) at specific measurement times, the specific changeover times being adapted to the specific measurement times such that in a specific time interval about a specific measurement time the semiconductor switches are not closed and opened, and a control unit (150) and a computer program for carrying out said method.

A drive system for a BLDC motor having poles implemented by separate coils that are activated in corresponding phases, which comprises a controller for controlling the level and phase of input voltages supplied to the separate coils; a controlled inverter with outputs, for applying phase-separated input voltages to each of the separate coils at desired timing for each input voltage, determined by the controller; a power source for feeding power to the controlled inverter; an up/down DC-DC converter for converting the feeding power to the input voltages according to a command signal provided by the controller. The controller is adapted to sample the instantaneous angle of the rotor of the BLDC motor; sample the input voltage input voltage and the current of each phase to obtain the input power P; and for each input voltage, calculate the phase difference value that corresponds to the input power and feeds the phase difference value to the up/down DC-DC converter, thereby causing the up/down DC-DC converter to apply each input voltage to its corresponding coil at a specific timing for obtaining an optimal match between each input voltage and the current that is being built up in the corresponding coil.

Systems and methods for sensorless trapezoidal control of brushless DC motors provide effective high-torque startup and low speed operation without the use of Hall effect sensors or encoders during motor operation. The systems and methods also provide the ability to boost signal-to-noise ratio for motor startup and low speed operation via an augmenting supply voltage. Sampling architectures and current-dependent inductance modeling architectures for the control systems are also described.

A motor controller comprises a switch circuit and a control unit. The switch circuit is coupled to a motor for driving the motor. The control unit generates a control signal to control the switch circuit. The motor controller determines a non-excitation time. When the motor is in a locked state, the motor controller enables the non-excitation time to be a variable value. The motor controller utilizes the non-excitation time to achieve a lock protection function. The motor controller determines whether the motor is in the locked state by detecting a rotor speed or a rotor temperature. Moreover, the motor controller further comprises a driving signal, where the driving signal has the non-excitation time.

Examples of methods and systems for compensating for the timing delay caused by the winding impedance of the motor coils and/or for non-ideal rotor magnet shapes and positions are disclosed. The example methods and systems may include generating a synthesized commutation signal compensating for non-ideal magnet shapes and positions (e.g., asymmetrical magnet positions) on a rotor and/or compensates for the timing delay caused by the winding impedance of the motor coils.

In accordance with an embodiment, a method includes generating a clock signal; generating a switching signal based on the clock signal; generating a synchronization signal having an edge transition corresponding to a predetermined phase of the switching signal; transmitting the synchronization signal to a master controller; receiving a frequency adjustment command from the master controller based on the transmitted synchronization signal; and adjusting a frequency of the clock signal based on the frequency adjustment command.

In accordance with an embodiment, a method includes generating a clock signal; generating a switching signal based on the clock signal; generating a synchronization signal having an edge transition corresponding to a predetermined phase of the switching signal; transmitting the synchronization signal to a master controller; receiving a frequency adjustment command from the master controller based on the transmitted synchronization signal; and adjusting a frequency of the clock signal based on the frequency adjustment command.

A method and a system for detecting a logic level of a rotor of a motor, and a motor are disclosed. The method comprises: obtaining an analog voltage output by a position sensor for a winding of the motor; setting a first commutation voltage and a second commutation voltage; generating a logic level according to the analog voltage, the first commutation voltage and the second commutation voltage; and performing angle correction on the logic level according to a first angle corresponding to the first commutation voltage and a second angle corresponding to the second commutation voltage. The first commutation voltage is a commutation voltage for triggering a rising edge, and the second commutation voltage is a commutation voltage for triggering a falling edge. This method may accurately identify the logic level corresponding to the motor rotor, improve uniformity of a commutation voltage and prevent fluctuations in motor speed.

A method of controlling a brushless permanent magnet motor includes measuring a mains power supply voltage of the motor. The method includes determining whether the mains power supply voltage lies within a first range representative of a first country's mains power supply or a second range representative of a second country's mains power supply. The method includes advancing commutation of a winding of the motor relative to a zero-crossing of back EMF in the winding where the mains power supply voltage lies within the first range, and retarding commutation of the winding relative to a zero-crossing of back EMF in the winding where the mains power supply voltage lies within the second range.

A motor drive receives a position feedback signal from an encoder operatively connected to the motor. The motor drive executes a speed regulator module on a first periodic interval to achieve desired operation of the motor, and the motor drive executes an additional module at a second periodic interval, occurring more frequently than the first periodic interval, to increase the resolution of the position feedback. The position feedback signal is provided as or converted to counts. The motor drive maintains a first counter with a running total of each count received as well as a second counter which generates a higher resolution value than the first counter. During each second periodic interval the motor drive increments the high-resolution counter by the number of actual counts detected within the corresponding first periodic interval. This high-resolution counter is used by the speed regulator to obtain desired operation of the motor.