Brushless motor driving system for driving outdoor fan of air conditioner

A brushless motor driving system for driving an outdoor fan of an air conditioner comprising:

• a single Hall probe for detecting the position of a rotor of a brushless motor for driving the outdoor fan of the air conditioner;
• an inverter circuit consisting of six switching elements connected in a three-phase bridge connection, DC terminals of said inverter circuit being connected to a main DC power source, AC terminals of said inverter circuit being connected to star-connected stator coils of the brushless motor;
• and
• control means for controlling the switching elements in the inverter circuit in synchronization with an output signal from the Hall probe, said control means including zero vector conduction means, wherein
• before starting the brushless motor, said zero vector conduction means turns either one of all of positive side switching elements and all of negative side switching elements to on-state and the other to off-state, thereby bringing the rotor to brake and stop at a first position.

A brushless motor driving system for driving an outdoor fan of an air conditioner comprising:

• a single Hall probe for detecting a position of a rotor of a brushless motor for driving the outdoor fan of an air conditioner;
• an inverter circuit consisting of six switching elements connected in three-phase bridge connection, DC terminals of said inverter circuit being connected to a main DC power source, AC terminals of said inverter circuit being connected to star-connected stator coils of the brushless motor;
• and
• control means for controlling the switching elements in the inverter circuit in synchronization with an output signal from the Hall probe, wherein said control means including DC excitation means, wherein
• before starting the brushless motor, said DC excitation means controls the switching elements in combination of first and second control modes to brake the rotor to stop, said first control mode making either one of all of the positive side switching elements and all of negative side switching elements to on-state and the other to off-state, for an either one switching element of one phase of a positive or negative side of the inverter circuit and the other side of the other two-phase, the second control mode applying a PWM-control to either one of the one-phase and two-phase switching elements, and a continuous conduction control to the other.

A brushless motor driving system for driving an outdoor fan of an air conditioner comprising:

• a probe for detecting a rotor position, the probe disposed in a stator of a brushless motor for driving the outdoor fan of the air conditioner;
• an inverter circuit consisting essentially of six switching transistors connected in a three-phase bridge connection, DC terminals of the inverter circuit being connected to a main DC power source, AC terminals of the inverter circuit being connected to star-connected stator coils of the brushless motor;
• and
• a switching transistor controller coupled to the switching transistors and in synchronization with an output signal from the probe so as to generate a predetermined magnetic field in a direction of braking a rotation of the rotor, the controller being under DC excitation, wherein, before a starting of the brushless motor, said DC excitation controls one switching transistor of one phase of a positive or negative side of said inverter circuit and switching elements of the other two phases of the other side to supply a pulse width modulation (PWM) controlled DC current to the stator coils of the motor, thereby bringing the rotor to brake and stop at a first position.