Differences Between Servo and Static Voltage Regulators: Choosing the Best Type for Your Applications
In
our modern world, where electricity is vital, ensuring a consistent power
supply is paramount. Voltage fluctuations pose a significant risk, potentially
causing damage to critical electrical equipment and resulting in costly repairs
and disruptions. To address this challenge, voltage regulators are deployed to
stabilize voltage levels and protect electronic devices. Among the popular
options are Servo Voltage Regulators and Static Voltage Regulators. In this
blog post, we will conduct a thorough comparison to assist you in making an
informed decision regarding the most suitable option for your requirements. Choosing
between a Servo Voltage Regulator and a Static Voltage Regulator depends on
several factors, such as the application, performance requirements,
environment, and budget.
A
Servo Voltage Regulator is an
electromechanical device equipped with a servo motor-controlled stabilization
mechanism. This motor operates by rotating either up or down, or clockwise or
anticlockwise. By connecting the servo motor shaft to the primary side of the
Buck-Boost transformer, the movement is synchronized to automatically manage
and rectify voltage fluctuations. This process ensures an optimal voltage
supply to the connected equipment
Static Voltage Regulators
are a category of regulators that leverage SMPS (Switched Mode Power Supply)
technology to control main line voltages. In Static AVRs, a switching topology
is employed, allowing for Pulse Width Modulation (PWM) directly in AC-to-AC
switching, effectively minimizing or eliminating harmonic distortions. This
innovative topology simplifies design complexities by reducing component count,
thereby enhancing efficiency and reliability. Typically, SCR/IGBT components
are integrated into the power stage of AVRs, tailored to their specific design
and rating.
Now let's compare the differences between the Voltage Regulators side by side.
|
Difference |
SERVO |
STATIC |
|
Performance |
It is an electromechanical device that utilizes a moving
servo motor to achieve voltage corrections. As a result, it has a slower
voltage correction speed (100 V/sec) compared to Static regulators. The correction
time of its servo stabilizer typically ranges between 50 milliseconds to
seconds. |
It has a pure electric circuit with no moving parts to
attain voltage corrections, resulting in an extremely low correction time of
> 3 milliseconds and an exceptionally high voltage correction speed
ranging from 360 to 500 V/sec. |
|
Reliability |
It achieves voltage correction in the electric load by
increasing or decreasing the winding count in the auto transformer through
the servo motor’s shaft. Therefore, the consistency of servo voltage
regulators mainly depends on the reliability of the servo motor. |
The reliability of the Static AVR depends on the
reliability of the power components, such as insulated gate bipolar
transistors (IGBTs) or silicon-controlled rectifiers (SCRs) in the power
stage. |
|
Auto Bypass |
The auto bypass mechanism complicates the process, making
it quite costly. This mechanism involves a break in the output voltage and
requires a transition time. |
Enables easy auto bypass because of the fast electronic
system that automatically transfers to bypass without any break in the output
voltage (Zero Transition Time), even in case of a fault. |
|
Efficiency |
Servo types are less efficient due to mechanical losses in
moving parts. |
Static types are more efficient |
|
Maintenance |
Uses motor and carbon brushes that result in wear and tear
and thus need frequent maintenance. |
Static AVR has a static mechanism that does not require
regular maintenance. |
|
Precision & accuracy |
Servo regulators are relatively less precise and accurate
at voltage regulation. |
Static regulators provide more precise and accurate voltage
regulation. |
|
Output Stability |
Stable Output |
Highly Stable Output |
|
Surge, Noise and harmonics filters |
Can be added additionally |
Can be added additionally |
|
Weight and size |
Servo regulators are generally heavier and larger due to the
inclusion of auto transformers and servo motors. |
Static regulators are lighter and compact as compared to
servo stabilizers. |
|
Protection |
The over-current protection can be achieved by installing
extra hardware, like Molded Case Circuit Breakers (MCCB), Over
voltage/current isolators. |
A Digital Signal Processor (DSP) control system
consistently senses the input and output voltages, the IGBT current, and the
load current, which quickly clears the over- current faults without any
additional hardware. |
Now, let's compare the applications of both regulators
Servo | Static |
· Textile Machinery · Printing machines · Lifts / Elevators · Industrial automation & CNC Machines · Packaging industry · Cold storage plants | · Hospitals and medical equipment’s · Laboratory Equipment · Computers & Network systems |
Consider the Load:
If you are dealing with sensitive equipment or critical applications, a servo
stabilizer is the better choice due to its precise voltage regulation.
Voltage Fluctuation Severity:
If your industry experiences frequent and severe voltage fluctuations, a servo
regulators wider correction range will be more suitable.
Long-term Investment:
If you are looking for a long-term investment and plan to use the regulator for
a wide range of equipment, a servo regulators versatility and durability make
it a more compelling option.
Conclusion
When deciding
between servo voltage regulators and static voltage regulators, consider
factors such as the required precision of voltage regulation, response time,
load type, and any specific features needed for your application. Consulting
with an expert in power conditioning solutions, like Makkays, can help you make
an informed decision tailored to your unique requirements.
To schedule a call or visit, please email us
at power@makkays.com