What Are Brushless servo drives?

Brushless servo drives are DSP based all-digital, precision servo drive amplifiers, which are able of supplying “16 A peak” current constant, as well as “32 A peak” up to 230 VAC. The brushless servo drives are designed to perfectly control the position or velocity and torque of a number of brushless torque and servo motors. The design of this servo drive simplifies the commissioning and set up of the brushless servo motors, as the system software of brushless servo drives needs little more than the ordinary ones.

Features of brushless servo drives:

• Several models which cover the major parts of the requirements of the servo application
• Line operated, 50/60 Hz, 115-240 VAC, single or three phase
• The complete digital design of brushless servo drives simplifies the drive tuning and drive set up and removes the analog drift
• Complete fault protection and “optically isolated I/O”
• PWM, ±10VDC, encoder-follower and step-direction control inputs accommodated
• Internal regenerative power control circuit, which requires an external resistor
• Graphical client interface based on PC for motion control, monitoring and commissioning. This interface is attached with the drive through an “optically isolated USB port”.

Benefits of brushless servo drives:

• High efficiency or power saving- The original drive technology of brushless servo drives use low power and offer a high efficiency. It represents a great money saving technique on the 24/7 application than the ordinary servo drives
• High inertial loads- The brushless servo drives use “sophisticated motion control algorithms” to take the advantage of high-torque capacity, offering direct-drive of high inertia loads such as the belt drives and flywheels. It is much more than the traditional servos. This servo drive also provides a smooth responsive pointing control.
• More torque in a lesser price- Brushless servo drives provides 2-4 times more constant torque in lesser price ($300-400 less) than the conventional servo motors.

AC Servo Drives – The Present Industrial Requirement

Servo drives are specially made electronic amplifier that is used to boost or run electric servo mechanisms. All the feedback signals that come from the servo mechanisms are actually monitored by the servo drives. A servo drive continuously adjusts even the smallest deviation from the normal behavior.

It should be known that the main function of a servo drive is to receive the command signals from the control system and then amplify it so as to transmit the electric current to the servo motor. This is done to produce motion that is proportional to command signal. In general, the command signal signifies a preferred velocity but it can also signify a desired torque if and when required. 

The servo drive gets the feedback of the actual status of servo motor control from the servo motor’s attached sensor. The actual status of the motor is then compared with the commanded motor status by the servo drive. The servo drive alters the voltage frequency of the motor in order to correct any small deviation from the desired commanded status. 

The servo motor control rotates at a speed which closely matches the velocity signal that is being received from the control system by the servo drive. There are several parameters like derivative gain, proportional gain and feedback requires proper adjustment so as to achieve the desired performance. This process of adjusting of the parameters is known as performance tuning.   
     

With the advancement in the technology of the microprocessor units there has been a constant growth of cost effective solution and development of a permanent magnet manufacturing technology for the servo motors. There has been a great improvement in the technological development of the high performance and high power semi conductor power devices. Thus, AC servo drives, AC servo motor has now become the basic technology for achieving automation control system in the present industrial scenario. 

AC servo drivers bring in the newest high speed DSP in order to meet the varied requirements of your high speed and high precision control system. The latest AC servo drives have a lot better dynamic feature and stability that the convention PI controls systems of yester years.  

Today’s AC Servo drives includes analogue apparatus within the control loop of a servo motor that helps to minimize the energy consumption and ensures maximum output. They assist in changing frequency of the AC voltage which is received by the motor with the use of electronic devices.