Stmicroelectronics S.r.l.

Stefano Baratto

Maurizio Di Meglio

Giuseppe D'Angelo

Giovanni Moselli

Francesco Pirozzi

Nicola Cesario

Mario Lavorgna

Francesco Giuffré

Umberto Macri

A method for determining duty-cycles of respective pulse width modulated (PWM), space vector modulated (SVM) control signals of an inverter, may include storing values of the duty-cycles as a function of a position of the multi-phase electric load in a look-up table. The method also may include determining a phasor angle representing applied sinusoidal voltages. The method also may include determining the duty-cycles as a function of the angle, and storing, in the look-up table, values of two pre-established waveforms relative to at least one duty-cycle as a function of the angle in at least two 60&#xb0; degree angular sectors, by at least, identifying which of six 60&#xb0; angular sectors the angle belongs, calculating a difference between the angle and an angular sector lower bound, and generating values as a function of the identified angular sector of the difference and the two pre-established waveforms stored in the look-up table.

Method and device for determining the duty-cycles of PWM control signals of an inverter

A method is for estimating an angular position of a rotor of a motor having position sensors along the circumference of a stator and generating digital signals that switch each time the rotor crosses certain angular positions. The method includes storing rotor angular positions at every digital signal switching, and determining for each rotor revolution a time interval elapsed between a current and a precedent switching edge of the signal generated. The method also includes estimating the angular position during a current rotor revolution by identifying which position sensor generated the last detected switching edge. The corresponding angular position and the time interval elapsed between two consecutive rotor crossings, through a same angular position, correspond to a sum between the angular position and a product between a fraction of the time interval elapsed from the corresponding precedent switching edge multiplied by 360&#xb0; and a number of polar pairs.

Method and device for estimating the angular position of the rotor of a brushless motor

A method estimates variations of position of the rotor of a motor having a plurality of uniformly spaced sensors that generate a position pulse at every rotation by a pre-established angle of the rotor. The method may include generating a first clock signal at a first frequency, generating a second clock signal at a second frequency multiple than the first frequency by a first factor, in each interval between two consecutive position pulses, counting the number of pulses of the first clock signal comprised in the interval, counting the number of pulses of the second clock signal comprised in the interval. The method may also include that each time the number of counted pulses of the second clock reaches the number of pulses of the first clock counted in an interval that precedes the currently considered interval, signaling that the position of the rotor has varied of an angle equal to the ratio between the pre-established angle and the factor.

Method and device for estimating variations of the position of the rotor of an electric motor

A method for estimating the state of a system, as well as an extended Kalman filter (EKF), allows nonlinear mathematical models to be used for describing the system. Accurate precision is provided since the method is based on an EKF technique while using a filter that implements a first degree Stirling approximation formula. The method may be used for estimating position and speed of a brushless motor, and may be implemented in a relative device. Such a device may be introduced in a control loop of a brushless motor of a power steering system for a vehicle to provide a countering torque on the steering wheel based on speed of the vehicle and a steering angle of the vehicle.

Method of estimating the state of a system and relative device for estimating position and speed of the rotor of a brushless motor

A control circuit is for an electric power plant including an asynchronous generator of an AC voltage, a motor to rotate a rotor of the asynchronous generator as a function of a first control signal of a developed motor torque, and a bank of capacitors coupled to the asynchronous generator and having a total capacitance varying as function of a second control signal. The control circuit may include a monitor circuit to monitor at least one parameter of the AC voltage, and a control signal generator circuit cooperating with the monitor circuit to generate the first and second control signals by soft-computing techniques both as a function of the frequency and of a representative value of an amplitude of the AC voltage to make the AC voltage have a desired amplitude and frequency.

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Naples, Italy

Stefano Baratto