Motor driving module and brushless DC motor system
A motor driving module is provided which includes a motor driving unit configured to control a PWM inverter on the basis of positional information and a control signal; a PWM inverter configured to output three-phase voltages on the basis of DC power according to control of the motor driving unit; a phase voltage estimating unit configured to output three-phase estimated voltages on the basis of the positional information, the DC power, and a voltage modulation index; and a position detecting unit configured to output the positional information on the basis of the three-phase estimated voltages, wherein the positional information is on an external motor that operates on the basis of the three-phase voltages.
1. A motor driving module, comprising:
a motor driving unit configured to control a pulse width modulation (PWM) inverter on the basis of positional information and a control signal, the motor driving unit including a reference voltage generator configured to generate a reference voltage that varies depending on a type of PWM;
a PWM inverter configured to output three-phase voltages on the basis of DC power according to control of the motor driving unit;
a phase voltage estimating unit configured to output three-phase estimated voltages on the basis of the positional information, the DC power, and a voltage modulation index that varies depending on the type of PWM and the reference voltage corresponding to the type of PWM; and
a position detecting unit configured to output the positional information on the basis of the three-phase estimated voltages,
wherein the positional information is on an external motor that operates on the basis of the three-phase voltages.
2. The motor driving module of claim 1 , wherein the voltage modulation index is a predetermined value on the basis of the PWM type.
3. The motor driving module of claim 1 , wherein the phase voltage estimating unit comprises:
a sinusoidal signal generator configured to generate a plurality of sinusoidal waves on the basis of the positional information; and
a phase voltage calculating unit configured to calculate three-phase estimated voltages on the basis of the plurality of sinusoidal waves, the voltage modulation index, and the DC power.
4. The motor driving module of claim 3 , wherein each of the plurality of sinusoidal waves has the same phase and frequency as those of the fundamental wave components of the three-phase voltages.
5. The motor driving module of claim 1 , wherein the position detecting unit comprises:
a back electromotive force (EMF) calculating unit configured to calculate three-phase back EMF on the basis of the three-phase estimated voltages; and
a position information detecting unit configured to detect the positional information on the basis of the three-phase back EMF.
6. The motor driving module of claim 1 , wherein the external motor is sensor-less.
7. The motor driving module of claim 1 , wherein the three-phase estimated voltages have the same phases and frequencies as those of the fundamental wave components.
8. A brushless direct current (BLDC) motor system, comprising:
a motor driving unit configured to control a pulse width modulation (PWM) inverter on the basis of positional information and a control signal, the motor driving unit including a reference voltage generator configured to generate a reference voltage that varies depending on a type of PWM;
a PWM inverter configured to output three-phase voltages on the basis of DC power according to control of the motor driving unit;
a BLDC motor configured to operate on the basis of the three-phase voltages;
a phase voltage estimating unit configured to output three-phase estimated voltages on the basis of the positional information, the DC power, and a voltage modulation index that varies depending on the type of PWM and the reference voltage corresponding to the type of PWM; and
a position detecting unit configured to output the positional information on the basis of the three-phase estimated voltages.
9. The BLDC motor system of claim 8 , wherein the positional information indicates on a rotor that is included in the BLDC motor.
10. The BLDC motor system of claim 8 , wherein the BLDC motor is sensor-less.