Introduction to Voltage regulator.
A voltage regulator is a device that generates constant output voltage even there is variation in input voltages. The fluctuations in the grid power supply voltage might be due to various reasons. The job of the servo regulator is to supply stable voltages at their output. Each AVR is designed for a specific input voltage range. When input voltage within that band, the voltage controller will correct it. Since it corrects voltages automatically, it is often called an automatic voltage regulator (AVR). Let’s understand all about this useful equipment that is nearly used in every industry.
Based on the working principle, there are two types of units. Servo motor controlled voltage regulators, also known as mechanical stabilizers. It corrects voltages by increasing or decreasing the number of transformer winding with the help of a servo motor. A static voltage stabilizer does not have any moving parts. Voltage is corrected using the Pulse width modulation (PWM) technique on the IGBT, SCR, or MosFET bridge. Due to this, static regulators are more efficient, faster, and durable than servo types of systems.
- Introduction to Voltage regulator.
- Difference between voltage regulator & stabilizer.
- Why we need voltage regulator?
- What is the voltage fluctuation?
- Disadvantages of voltage fluctuation.
- What are the benefits of using a voltage regulator?
- Applications of voltage stabilizer.
- The Best features of voltage regulators.
- Optional features of servo regulator.
Difference between voltage regulator & stabilizer.
There are no differences between the two when it comes to purpose. The objective of both devices is to offer contact voltage at its output. However, the distinguishing factor is the method of achieving constant voltage. A voltage regulator stabilizes the load current to generate a stable output voltage. On the other hand, a voltage stabilizer reaches stable output voltage by reducing load voltage fluctuation.
In other words, a stabilizer takes the clue about under or overvoltages from the input. But, the regulator takes feedback from the output. Hence, the AC voltage stabilizer can not compensate for voltage drop due to varying load. So if there is a changing load, you need voltage regulation, and for the fixed load, you need voltage stabilization.
Why we need voltage regulator?
AVR is generally used in countries with poor infrastructure for power generation, transmission, and distribution. Also, it is required in heavily industrialized modern nations, which observe low voltages in industries due to weak grids. Please note that power grid voltages are designed for the linear load (resistive load). And when grid subject non-linear load (inductive or capacitive) then sudden high or low current demanded from the grid which tends to sag or swell in grid voltage. In other words, it gives rise to voltage fluctuations that need to address to avoid losses.
Electric Grid is very complex. Even modern system is based on high-inertial generation, rugged transmission lines, and the latest distribution system. But still, we can observe unstable voltages in our facilities. Voltage regulators are the answer to varying voltages. It can correct voltages with high speed to ensure stable, safe, and clean voltages for your essential loads. It is imperative to treat voltage fluctuation to avoid many kinds of forfeiture.
What is the voltage fluctuation?
Any increase or decrease in value of desired voltage for a short or long time is a voltage fluctuation. It creates severe power quality issues. Ideally, we need a stable power supply. But, a sudden drop or jump in voltages and currents can cause undesirable conditions. A fluctuation is caused by one or all of the following issues.
It is nothing but the dip in the voltage. Whenever voltage drops more than 10% in the steady-state value, it is considered a sag. For example, if the regular 230V supply decrease to less than 207V. The common reason for sag is sudden demand of high current due to switching on of heavy load. A suitable voltage regulator can counter the sags.
It is the opposite phenomenon of the sag. More than a 10% increase in the voltage for a short period is a Swell. It causes due to a sudden drop in the load. If 230V supply jumps more than 253V, then it is considered as a swell. It creates power quality issues and sometimes damages the machines.
It is nothing but a sag that is persistent for more than a minute. The common reason behind the Undervoltage is a sag with underrated power cables and overloaded transmission transformers.
Any swell that lasts for more than a minute is an overvoltage. It often causes the burning of machines, MCCBs, power failure, and accidents.
It is nothing but a swell that is much stronger in magnitude but lasts for a short time. A voltage transient can be in the range of a few volts to a thousand volts which exist for micro to the millisecond. Any sudden release of stored energy like a lightning stroke can cause it. Faulty contractor, capacitor bank, arcing in a breaker can cause a surge in voltages.
Disadvantages of voltage fluctuation.
In short, voltages fluctuation can bring losses to your business. It can make losses in terms of finance, human life, or person-hours. Please note that every industry consists of different types of equipment. It can be computers, PLCs, CNC machines, motors, etc. And fluctuations have an ill effect on every component in one or another way. CtrlTech voltage regulators are capable of correcting it.
Affect of constantly changing voltages are as follow:
- It can cause permanent damage to the machines.
- Also, voltage fluctuation decreases the life span of the industrial equipment.
- It can cause overheating of motors and hence reduces their efficiency.
- Overheating due to the varying voltages can damage the insulation.
- It can increase spending on electrical bills.
- Financial losses due to faults and downtime.
What are the benefits of using a voltage regulator?
There are several advantages of owning a voltage stabilizer. It provides an economically safe power supply for all your devices. Some of them are as follow:
- Voltage regulator protects your machines from overvoltages, overcurrent, spikes, and surges. Thus, it saves your property and avoids financial losses.
- Voltage stabilizers offer a stable power supply to the equipment. Hence, it increases their lifespan and reduces maintenance costs.
- It avoids power-related accidents and protects human life.
- AVR is the most economical equipment that provides safe power. It is much cheaper than an Uninterruptible power supply.
- Return on investment of this device is much faster. In most cases, the cost of the regulators is a fraction of the cost of the load. But, AVR protects devices from all power problems.
Applications of voltage stabilizer.
Voltage stabilizers are well known for offering voltage stability. Due to the same reason, you can see them being used for numerous industrial applications. Let’s explore some of the most prominent industrial applications where you can see an automatic stabilizer. If you have any requirements related to these applications, you can purchase an AC voltage regulator.
CNC machines deliver their work with very high precision. In fact, perfect calibration is extremely important to ensure the proper functioning of a CNC machine. Precise electrical components present within a CNC machine would manage these calibrations. It is a reason why you should ensure the protection of all those electrical components against fluctuations in electricity. A voltage regulator will be able to provide the assistance you need. Once you invest in a voltage regulator, you can ensure the long-term protection of the CNC machines you have.
Every residential and commercial building has lifts and elevators. The heart of the lifts and elevators is the motor that keeps them on the move. Hence, any failure to this motor can stop working of the elevator. Commercial lifts are fitted with a heavy-duty 3-phase motor and it also thermal sensor. The voltage fluctuation can cause heating of the motor coils and loss of the magnetic current rotation. Also, it might cause phase failure or permanent damage to the elevators. Thus, a voltage regulator is needed to provide a stable power supply to lifts.
Diesel generators are power backup devices of high KVA capacity. It is electromechanical equipment that generates power. Hence, even high-quality generators show fluctuations in their output voltage. The unstable output voltage can damage sensitive electronic and industrial equipment. Thus, a servo voltage regulator is recommended to connect at the output of the generator. The capacity of the voltage stabilizer should be at least 25% more than that of the generator rating.
You can see servo motor controlled and other types of voltage stabilizers in the packaging industry as well. There are multiple heavy machines present in the packaging industry. These machines are running on electricity. In most instances, you can find automated machines that run along with each other throughout the production line.
If there is an unstable voltage supply, all these types of machinery can get affected. It will not just bring your production line to a halt but can also lead you to problems with getting them replaced. If you are not ready to take any such risk, you should get a voltage regulator.
When you are using a voltage regulator, you will be able to cut down all sorts of unnecessary expenses. Moreover, you can ensure the safety of devices from electrical hazards. You can also keep all the machinery running in perfect condition as well.
The machines used to sew clothes should receive a three-phase electricity supply to work properly. However, three phase electricity supply can often cause voltage fluctuations. These voltage fluctuations can cause damages to the machines. This is where the voltage regulators would come into play. They can provide all the protection needed by the electrical appliances in a garment against voltage fluctuations. People will be able to use them without encountering any technical issues, such as overloading.
You can often see an AC voltage regulator at hospitals and other similar environments. Numerous expensive medical devices are functioning within a hospital. Hence, it is vital to ensure the protection of all these devices. They are responsible for saving the lives of people. However, these devices would only work within their prescribed voltage limitations. Even if you provide a power supply to them with a small fluctuation in voltage, you will end up getting them damaged. It is the reason why voltage stabilizers are available in hospitals.
The voltage stabilizers you can see in a hospital prevent the delicate and expensive medical machinery and instruments from overloading. MRIs and CT scanning machines are perfect examples of such devices available in a hospital. Before supplying voltage to these devices, the voltage regulator will control voltage.
The pump room is installed with water pumps for water distribution or dewatering purposes. Pumps are susceptible to power quality. Any sudden surge, sag, or swell in the voltages can damage the pump. Hence, it is very crucial to ensure stable electricity for these pumps. CtrlTech offers the best servo motor voltage regulators specially designed for the pump rooms. It is available from 10 to 500kVA rating with three and single-phase configurations.
The Best features of voltage regulators.
In short, a good quality voltage regulator should have fast voltage correction, be reliable, and with high input voltage window. There are many other factors too that decide the quality of a good voltage stabilizer. An ideal unit should have at least the following features:
- Voltage correction speed: High voltage correction speed is desirable. It should be between 70-200 volt/second. High voltage correction speed will ensure correction in voltage before you load switch off. Especially computers can reboot even with minor interruption. A static voltage stabilizer offers correction speed up to 1000 V/sec.
- Wider input voltage window: Voltage regulator with broader input voltage window. It is generally defined as the percentage of input voltage, i.e., ±20%, ±25%, ±30%, etc. It implies that the unit can correct voltages even if the input voltage is too low or high. For example, a servo stabilizer with an input of 275 to 460V can supply stable output voltages when the input voltage is anywhere between 275 to 460V.
- Voltage Regulation: It is always desirable that the servo voltage regulator should deliver precise output voltage. Generally, a good quality stabilizer has ±1% voltage regulation which is acceptable. AVR should precisely meet output regulation as a percentage of the nominal input supply voltage.
- Efficiency: High efficiency is always desired, so that system loss is less. It also indicated the high quality of components in stabilizers. The quality of transformers plays a vital role in deciding the overall efficiency of the equipment.
- Voltage cut-off: In case of input voltage higher or lower beyond designated values, then the servo regulator should cut off the output with audible and visual alarm. The system should have fast-acting breakers and isolators to ensure the same.
- Overvoltage Protection: A automatic servo voltage stabilizer should have overload protection. And it should isolate the load connected to it and give an audio-visual alarm.
- Independently in a three-phase system. It will help fast regulation even at work stabilizer at 100% unbalance load and input voltages. Also, an independent phase control voltage regulator can work in the case of the non-symmetric mains supply.
Optional features of servo regulator.
- Bypass: It is better to have a bypass facility in the stabilizer if it serves a critical load. Bypass helps to connect regulator input directly with its output by bypassing the circuitry of the voltage regulator. This feature is helpful if you like to repair or do maintenance work of the unit without shutdown of load.
- Input line filter: It suppresses unwanted radio frequency components. The unit should have an input line filter if it is used to supply voltages to applications with electronic circuits like radio stations, TV studios, and datacentre.
- Reverse phase protection: In case of phase reversal, at input voltage stabilizer should isolate load. Thus, it will disconnect its output. Most of the units consider a phase reversal as an input failure. A phase correction module is recommended at the input or inbuilt option in the stabilizer.
- Surge Suppressor: There is always the possibility of voltage surge due to lightning stroke, heavy load switch off, arcing. Also, sudden high voltage spikes can generate due to an inefficient electric power network. Thus voltage regulator should have a surge suppressor to bypass the high voltage.