Design Of A Kind Of Direct Current Servo Motor Driver

In resent years，under the support and guidance of the relevant government departments, theelectric vehicle industry is gradually moving towards the market. As the supporting equipmentindustry of electric vehicle, the research of mechanical arm to replace electric vehicle battery has agood practical value. This topic mainly designed a driver to drive the direct current servo motorused in multi-joints mechanical arm. The direct current servo motor driver with stable performanceplays a very important role in the overall performance of mechanical arm and has importanteconomic and scientific value.This paper firstly introduced the application and development trend of the direct current servomotor driver, then analyzed the development trend of the driver power supply. The whole designscheme of the driver and the parts of the driver were introduced and illustrated in detail. Generallythe driver can be divided into three parts, the first part is AC/DC transform circuit with APFC(active power factor correction). Using special control chip, the driver achieved high power factor,the utilization rate of power gride and the power supplyload capacity of the equipment wereeffectively improved.at the same time supplied400V stabilized direct voltage for later stage circuit;The second part is a DC/DC conversion half bridge LLC resonant converter circuit.LLC circuit hasgreat advantage in constant voltage output.It can provide stable voltage for the servo motor. Thispart realized zero voltage switching to the switch tube and zero current switching to the rectifierdiode, which reduced the circuit loss and improved the driver’s efficiency; The third part is thedirect current servo motor directly driving circuit, which using PWM driving mode to drive directcurrent servo motor. This paper analyzed the basic working principle of whole circuit, andexplained the selection of electronic components, finally completed the design of the whole circuit.This paper also introduced the design of electromagnetic compatibility for driver, the tips ofPCB layout and the design of system reliability.This paper analyzed the causes of electromagneticinterference in circuit and put forward some measures to restrain them. The PCB layout andelectrical isolation were explained.Finally, methods such as the circuit topology, electroniccomponents selection, drive packaging were introduced to improve the reliability.Finally tested the120W direct current servo motor driver, illustrated the key point workingvoltage waveform in the circuit of the driver and analyzed them. After testing, the results showedthat the drive worked properly, the power factor was higher and the current total harmonic waslow.The whole efficiency meet basically therequirements and the direct current servo motor positiveand negative going motion stably.