Brushless dc motor controller system hardware design

Small make up today is to introduce the hardware design of the control system of brushless dc motor knowledge, are interested and see it together. Hardware design including main circuit and control circuit of brushless dc motor (BLDCM), the main circuit is composed of dc power supply, MOSFET full bridge circuit and the motor controller of ontology. Control circuit with DSP chip TMS320LF2407A as the core, with current and speed of the inner ring, the location for the outer ring, by the power drive circuit and interface circuit and protection circuit. This system adopts the way of PWM control system for the brushless dc motor. Its working principle is: ac power through the isolated transformer, rectifier voltage regulator, voltage regulator rectifier and filter into the inverter as the dc power supply; System by photoelectric encoder as the position sensor to detect motor rotor position in order to determine the inverter power phase sequence. System adopts three-phase y-connected all control circuit, using the two conduction mode. Every moment has 2 power tube conduction, every cycle (16 60 ° Angle) Reversing a times, each time the reversing a power tube, each power tube conduction Angle 120 ° of electricity. By DSP minimum system itself or an external EPROM ( Block or EEPROM) , RAM, PLL clock module, reset circuit, decoding circuit, etc. PLL clock module, including crystal oscillator and loop filter element and power supply connection part. Reset circuit: electric automatic reset, manual reset and + 3. 3 v power supply voltage under-voltage protection reset function. Power conversion: due to the power supply voltage MS320LF2407 is 3. 3 v, need to be converted to 3 to 5 v power supply. 3 v to the CPU power supply, the output current up to 1 a TPS76833QPW as 5 v to 3. 3 v conversion chip. Main circuit in dc regulated power supply, the full bridge circuit made up of six MOSFET field-effect tube. T1, T3, T5 three p-channel MOSFET structure on bridge, gate level G plus negative voltage when conduction. T2, T4 and T6 three n-channel MOSFET under the bridge, gate level G plus positive voltage when conduction; Six feedback diode D1 D6, using low loss snubber circuit, small switch loss, reliable work. Brushless dc motor controller of three-phase winding at any time in the operation of the only two phase conduction, and for the same current, so in the main circuit through a feedback resistor Rf instead of the conventional current sensor, the voltage value Uf calculated to get the line current indirect measurements. Rf can complete current detection, current limit and the function of over-current protection. Voltage Uf one through the filter, amplification, the ADC module after clipping into TMS320LF2407 as current feedback value; One also after filtering, enlarge the voltage comparator, system Settings of the current value as a voltage comparator reference voltage, voltage comparator output into LF2407A PDPINTA pin, once more than the set value, the armature current, the low level of the PDPINTA pin is pulled, DSP internal counter stop counting, all PWM in high impedance state; An interrupt signal at the same time, notify the DSP is unusual, and in the interrupt handler, the fault judgment. , thank you very much for reading, whether you fully understand the above content, if have not understand questions, welcome to inquire. Small make up: Candy