What Is a Manostat?

A voltage regulator is a device that stabilizes the output voltage. The voltage regulator is composed of a voltage regulating circuit, a control circuit, and a servo motor. When the input voltage or load changes, the control circuit performs sampling, comparison, and amplification, and then drives the servo motor to rotate, so that the position of the carbon brush of the voltage regulator is changed. By automatically adjusting the coil turns ratio, the output voltage is kept stable.

Chinese name: Stabilizer
Foreign name: Pressure regulator

Technical Parameters: A. Regulator has an input voltage adaptation range
Features: Can automatically adjust the output voltage balance
Country: China

Regulator structure

A typical switched-capacitor converter consists of four large MOS switches in a typical switching sequence, doubling or halving the input supply voltage. The energy transmission and storage are provided by external capacitors. The company takes the example of China s isolation transformer products in the market environment, production and operation, product import and export, industry investment environment and sustainable development issues. On this basis, China has made industry development trends The analysis and forecast of qualitative and quantitative analysis are presented. Engaged in the production, development, and sales of low-voltage supporting products such as transformers, voltage regulators, and voltage regulators. "Insist on corporate innovation. The main products are: SBW high-power compensation power regulators, SBW-F split-mode power regulators, SVC high-precision automatic AC voltage regulator, precision purification voltage regulator, microcomputer non-contact voltage regulator, SG \ SBK isolation transformer, OSG \ QZB autotransformer, ZSG \ ZDG rectifier transformer, SSG servo transformer, DN resistance welding Complete set of electrical equipment such as water-cooled transformers, reactors, contact autocoupling regulators, column-type high-power electric voltage regulators, etc. The product design is novel, small in size, beautiful in appearance, and has the advantages of low loss, low noise, and impact resistance. Used in industrial and mining enterprises, textile machinery, printing and packaging, petrochemicals, schools, shopping malls, elevators, post and telecommunications, medical machinery and other places that require normal voltage guarantee.

During the first part of the switching cycle, the input voltage is applied to a capacitor (C1). During the second part of the switching cycle, charge is transferred from C1 to the second capacitor C2. The most traditional switch-capacitor converter is constructed as an inverter converter, in which C2 has a positive ground terminal and its negative terminal transmits a negative output voltage. After a few cycles, the voltage through C2 will be applied to the input voltage. Assuming there is no load on C2, no losses on the switch, and no continuous resistance in the capacitor, the output voltage will be exactly the negative of the input voltage. In reality, the efficiency of charge transfer (and the accuracy of the resulting output voltage) depends on the switching frequency, the resistance of the switch, the value of the capacitor, and the continuous resistance. A similar topology doubler uses the same switches and capacitor banks, but changes the ground connection and input voltage. Other more sophisticated variants use additional switches and capacitors to achieve other conversion ratios of input voltage to output voltage, and in some cases, use a dedicated switching sequence to produce a fractional relationship (for example, 3/2). In the simplest form, switched capacitor converters do not have voltage regulation. Some new National Semiconductor switched-capacitor converters have an automatically adjusted gain level to produce a regulated output; others use a built-in low-dropout linear regulator to produce an unregulated output.

Technical parameters of voltage regulator

A. The regulator has an input voltage adaptation range. The IEC standard is that the input voltage changes within the range of ± 20 of the rated value. If the range is exceeded, an automatic audible and visual alarm will occur and the output voltage cannot be stabilized within the required range.

B. The output voltage adjustment rate is the effect of the change in the output caused by the change in the input voltage. When the load is the rated value, the input voltage is adjusted upward from the rated value to the upper limit and the lower limit according to the source voltage range. Maximum change in output voltage (±). The smaller the value, the better. It is an important indicator to measure the performance of AC regulator.

C. Load regulation: It is the effect of the change in output caused by the change in load. Change the load current and measure the change in output voltage (±). The smaller the value, the better. It is also an important indicator to measure the performance of the AC regulator.

D. Relative harmonic content of output voltage (also known as output voltage distortion), usually expressed as THD, is the ratio of the total effective value of the harmonic content to the effective value of the fundamental wave. When the load is rated, the input voltage distortion meets the benchmark Under the conditions (usually should be less than 3), measure the output voltage distortion when the input voltage is the lowest value, the rated value and the highest value, whichever is the greater. The smaller the value, the better.

E. Efficiency: is the ratio (percentage) of the output active power P0 to the input active power Pi,

F. Load power factor

The capacity of the regulator is expressed in volt-ampere (VA) or kilovolt-ampere (KVA) values. In addition to pure resistive loads, there are inductive and capacitive loads in the load, that is, in addition to the active power, there is no Work power. This pointer reflects the ability of AC stabilized power supplies with inductive and capacitive loads.

For general AC stabilized power supply, the load power factor cos is 0.8. When the product is 1KW, the output active power (that is, the capacity of the resistive load) is up to 800W. If the product is expressed in 1KW (cos is still 0.8), the The output active power is 1KW. At this time, the output power S = 1000 / 0.8 = 1250VA. When the load power factor is small, it means that the power supply equipment has a strong ability to adapt to reactive loads.

G. The parameters of the AC voltage regulator include output power, input frequency, source frequency effect, random deviation (time drift), no-load input power, source power factor (this value is different from the load power factor, hope the bigger the better, the largest For 1), the source current relative harmonic content, audio noise and other items, three-phase AC stabilized power supply, and three-phase output voltage imbalance, etc., the definition and test methods of these pointers can refer to relevant standards.

Application scope of voltage regulator

Voltage stabilizers can be widely used in electronic computers, precision machine tools, computed tomography (CT), precision instruments, test equipment, computers, industrial and mining enterprises, oil fields, railways, construction sites, schools, hospitals, post and telecommunications, hotels, scientific research and other departments. Elevator lighting, imported equipment, production lines and other places that require stable power supply voltage. It is also suitable for users at the end of low-voltage distribution networks with low or high power supply voltages and large fluctuations, and electrical equipment with large load fluctuations. It is particularly suitable for all voltage-stabilized electrical places that require high grid waveforms. The high-power compensation type power regulator can be connected to firepower, hydraulic power and small generators.

Regulator function introduction

Voltage stabilizer is a kind of power supply circuit or power supply equipment that can automatically adjust the output voltage. Its role is to stabilize the power supply voltage that has large fluctuations and fails to meet the requirements of electrical equipment within its set value range, so that various circuits or electrical equipment The equipment can work normally under the rated working voltage.

The first power regulators stabilized voltage by the bounce of relays. When the grid voltage fluctuates, the automatic correction circuit of the power regulator starts to make the internal relay act. Forcing the output voltage to stay near the set value, this circuit has the advantages of simple circuit, but the disadvantage is that the voltage regulation accuracy is not high and every time the relay jumps and shifts, it will cause a momentary interruption of the power supply and spark interference.

This interferes with the reading and writing of the computer equipment, which can easily cause the computer to have an error signal. In severe cases, it can also damage the hard disk.

Most high-quality small voltage regulators use a motor to drag a carbon brush to stabilize the voltage. Such voltage regulators have little interference with electrical equipment and the voltage regulation accuracy is relatively high.

Regulator operation method

Regulator error flag

The error flag is an open-collector output, which sends a signal when the regulated output voltage is 5% (typical) below the rated output voltage. Initially, the error flag is low until the output voltage reaches 95% of the rated output voltage. In some cases, there will be a delay in mislabeling during power conversion. This delay is set by an external capacitor and can be used as a power-on reset function to reset the microprocessor to power up. If the status is "Error", the output voltage is low so that the output of the open collector is high (the marked transistor shows OFF). When the output voltage is within 5% of the rated voltage, the output of this mark is low.

Regulator switch

The "On / Off" or "Stop" function enables the regulator to be turned on or off with power applied. Although in the "off" or "shutdown" mode, the regulator's supply current is reduced to a lower level because the output is disabled, the internal bias circuit is still running. When re-enabled, the regulator will re-regulate the output voltage much faster than if the input voltage were turned off and on. If the display is on, the regulator will be activated by a logic high level. Otherwise, it will be started by a logic low.

Regulator adjustment

In switching regulators and switched capacitor converters, an internal oscillator is used to set the switching frequency of the output transistor. The value of this switching frequency can determine some external components used in the converter, determine the frequency of the noise generated by the converter, and affect the performance of the converter. Some converters allow the switching frequency to be changed by adjusting the internal oscillator frequency ("frequency adjustment") or by synchronizing the oscillator with an external power supply ("synchronization"). In general, by increasing the switching frequency, smaller components (capacitors, inductors) can be used in the converter output stage. This may reduce the efficiency of the converter as switching losses increase unless higher quality components are used at the same time. Higher frequency converters that perform well will have faster transient response than lower frequency converters. If there are several converters on a board, it is usually best to synchronize them to a common source. This controls the noise generated throughout the batch and minimizes any "knock frequency" that may occur. This issue is usually important for high-power converters, such as 5W or higher. In many cases, the switching frequency can only be increased from its preset value. The product data sheet will indicate the frequency range for this feature. ^[1]

Regulator capacity curve

Auto-coupled voltage regulator (single-phase 0.5kVA ~ 3kVA, 10k horizontal and below, three-phase 9kVA and below) When the input phase voltage is lower than 198V, the output capacity begins to decrease; when the input phase voltage is equal to 160V, it drops to 50% of the rated capacity of the regulator. Therefore, special attention should be paid to reducing load derating at the low end of the power supply voltage, so as not to overload the voltage regulator and burn out;

The auto-regulator can output 220V and 110V at the same time. But even when the output is all 110V, the load of the voltage regulator cannot exceed 50% of the rated capacity, otherwise it will be overloaded.

Connect the regulator input to the power distribution board, and install a fuse that meets the power guarantee rate of the instrument on the user power distribution board to ensure the safety of electricity use.

Connect the power supply of the electrical equipment to the output terminals of the instrument. Note that the rated input voltage value of the electrical equipment should be consistent with the output of the voltage regulator. Do not connect it incorrectly.

First turn on the power switch of the voltage regulator, and the work indicator light is on. Observe whether the value indicated by the voltmeter is normal. When the output voltage is normal, turn on the power switch of the electrical equipment, the voltage regulator can automatically adjust the voltage and supply power normally.

When the electrical equipment is not used for a long time, please turn off the power switch of the electrical equipment to reduce power consumption and extend the life of the regulator.

Do not overload the voltage regulator. When the mains voltage is low, the output capacity decreases, and the load on the regulator should be reduced accordingly.

When using electrical appliances such as refrigerators, air conditioners, water pumps and other equipment with motors, a voltage regulator with a capacity greater than 3 times should be selected to prevent the device starting current from exceeding the regulator fuse current or overcurrent protection circuit breaker current to make the regulator The fuse is blown or the circuit breaker is tripped or the voltage drop is too large to work.

The wires connected to the voltage regulator should have sufficient load surface to prevent heat generation and reduce voltage drop. For voltage regulators with a capacity of 2KVA or more, terminals are used for connection. A single copper wire should be used, and the terminal screws should be tightened as much as possible to prevent the connection from heating up.

Whether it is a single-phase or three-phase voltage regulator, after all input and output lines are connected, the power switch of the load should be turned off, and then the voltage regulator should be turned on. After the output voltage is normal, turn on the power switch of the load.

Use the saturation characteristics of the core material to show that the output voltage is basically stable.

Advantages: reliable operation, strong overload capacity, automatic protection when output short circuit, simple structure, large voltage stabilization range, strong anti-interference ability.

Disadvantages: heavy weight, large size, high price, high noise, high core temperature, and high requirements on the input power supply frequency.

Applications: computer-related products, medical monitoring systems, program control systems, automatic test equipment, radio and television equipment, post and telecommunications equipment, automatic plug-in machines, production lines, printing equipment, plastic injection equipment, ATMs, SMT equipment, scientific research experiments, etc.

Basic structure of magnetically amplified AC voltage regulator

The output voltage is stabilized by changing the magnetic resistance of the magnetic amplifier transformer connected in series in the primary circuit of the self-propagating transformer.

Advantages: high voltage regulation accuracy, fast response time

Disadvantages: heavy weight, large size and high price.

Application: Precision electronic equipment, medical equipment, computer room, laboratory, product aging and testing.

Regulator role

Stabilizer With the rapid progress of society, the use of electrical equipment is increasing. However, the aging and lagging development of power transmission and distribution facilities, as well as poor design and insufficient power supply, cause the end-user voltage to be too low, while the line-end users often have high voltages, especially for high-tech technologies and high-tech Precision equipment is like an untimed bomb. As a public power grid, the city power system is connected to thousands of various loads. Some of these large inductive, capacitive, and switching power supplies not only obtain power from the power grid, but also cause damage to the power grid itself. It affects and deteriorates the power supply quality of the power grid or local power grid, causing the mains voltage waveform distortion or frequency drift. In addition, accidental natural and man-made accidents, such as excessive load voltage, earthquake, lightning strike, open or short circuit of the power transmission and transformation system, will endanger the normal supply of power and affect the normal work of the load.

Unstable voltage can cause fatal injury or malfunction of the equipment, affect production, cause delays in delivery, unstable quality and other aspects. At the same time, it will accelerate the aging of the equipment, affect the service life and even burn down the accessories, causing the owners to face the need for maintenance or to update the equipment in a short period of time, wasting resources; in serious cases, even security accidents cause immeasurable losses.

Therefore, the use of voltage regulators is essential for electrical equipment, especially high-tech and precision equipment with strict voltage requirements.

Product Categories

The voltage regulator has a large AC voltage regulator of several tens to several thousand kilowatts, which is a working power supply for large-scale experiments and industrial and medical equipment. There are also small AC-to-kilowatt AC regulators that provide high-quality power for small labs or home appliances.

According to the different output characteristics of voltage regulators, voltage regulators are generally divided into two categories: AC voltage regulators (AC stabilized power supplies) and DC voltage regulators (DC stabilized power supplies). The following focuses on the DC regulated power supply, referred to as the regulated power supply for short.

According to the working state of the regulating tube, the regulated power supply is often divided into two categories: linear regulated power supply and switched regulated power supply. In addition, there is a small power supply using a Zener tube.

Switching regulator

Stabilizer Switching regulators use an output stage to repeatedly switch between "on" and "off" states to produce an output voltage with energy storage components (capacitors and inductors). Its adjustment is realized by adjusting the switching timing according to the feedback samples of the output voltage. In a fixed-frequency regulator, the switching timing is adjusted by adjusting the pulse width of the switching voltage, which is called PWM control. In a gated oscillator or pulse-mode regulator, the width and frequency of the switching pulses remain constant, but the "on" or "off" of the output switch is controlled by feedback.

According to the arrangement of switches and energy storage components, the output voltage can be greater than or less than the input voltage, and multiple output voltages can be generated with one regulator. In most cases, with the same input and output voltage requirements, a pulsed (buck) switching regulator is more efficient than a linear regulator in switching power supplies. Compensation --- High-precision AC compensation stabilized power supply (single-phase 0.5kVA and above, three-phase 1.5kVA and above) with compensation transformer and 110V output

Parametric regulator

Linear regulator LDO is a linear regulator. Linear regulators use transistors or FETs that operate in their linear region, subtracting excess voltage from the input voltage of the application to produce a regulated output voltage. The so-called voltage drop voltage refers to the minimum value of the difference between the input voltage and the output voltage required for the regulator to maintain the output voltage within 100mV of its rated value. Positive output voltage LDO (low dropout) regulators typically use power transistors (also known as pass devices) as the PNP. This transistor allows saturation, so the regulator can have a very low dropout voltage, usually around 200mV; compared to a conventional linear regulator using NPN composite power transistors, the voltage drop is around 2V. The negative output LDO uses NPN as its transfer device, and its operation mode is similar to that of a positive output LDO PNP device.

Newer developments use CMOS power transistors, which provide the lowest dropout voltage. With CMOS, the only voltage drop across the regulator is caused by the ON resistance of the load current of the power supply. If the load is small, the voltage drop produced by this method is only tens of millivolts ^[2] .

Regulator for laser cutting machine

According to the use requirements of high-power laser cutting machines, combined with the current situation of power supply in China, a voltage regulator for laser cutting machines should be strictly formulated, and energy-saving products specially developed for stabilizing AC voltage. When the power supply voltage of the distribution network fluctuates or the load changes, it can automatically ensure the stability of the output voltage. It must have the characteristics of large capacity, high efficiency, wide voltage stabilization range, no additional waveform distortion and phase shift, fast strain time, and stability. It has complete alarm protection functions such as short circuit and mechanical failure. At the same time, the volume should be as compact and small as possible and easy to use.

Introduction

Electricity can generate magnetic fields, and magnetic fields can be converted into electricity. When alternating current is applied to a coil, an alternating magnetic field is generated. Then, the alternating magnetic field is passed through another coil, and a voltage is induced in the other coil. This is the principle of a transformer.

The voltage regulator uses the principle of negative feedback. There is a circuit in the voltage regulator that can detect the change of output voltage (the voltage-dividing resistor sampling circuit at the inverting input of the error amplifier. This circuit can be reduced to only one integrated chip). When the output voltage changes, the circuit that detects the output voltage change is provided by the chip to the private server motor, and the servo motor drives the swing arm to automatically adjust the position of the brush to stabilize the output voltage. This is the simplest voltage stabilization. Device.

In summary, the transformer does not have the function of voltage stabilization, but it is possible to design a transformer with the function of voltage stabilization by using negative feedback technology, but this is not the case for general transformers. The output voltage change of the transformer in a certain range of use is not large, and what we call voltage regulation is not a concept.

All voltage regulators use the same technology to stabilize the output voltage. The output voltage is sampled by a voltage-dividing resistor connected to the inverting input of the error amplifier, and the non-inverting input of the error amplifier is connected to a reference voltage. The error amplifier always tries to force the inputs on both ends to be equal. To this end, it provides load current to ensure stable output voltage (that is, negative feedback)

The voltage stabilizer and UPS are different concepts, but many friends always mistakenly believe that the voltage stabilizer is UPS, which is essentially different; UPS is divided into online and backup, and the general computer is equipped with backup. It belongs to a kind of emergency power supply, voltage stabilizer: it is designed for voltage instability, mainly used for back-end equipment protection, and has better protection functions for equipment. Generally large UPS must also be equipped with a voltage stabilization bypass system, that is, an LW-PLG voltage regulator. The concept of voltage regulator was introduced above. What is UPS?

The Chinese meaning of UPS is "Uninterruptible Power Supply", which is the abbreviation of "Uninterruptible Power Supply" in English. It can guarantee that the computer system will continue to work for a period of time after a power outage so that users can save the file in an emergency, so that you will not be affected by the power outage or lost. data. It has two main functions in computer systems and network applications: first, emergency use to prevent sudden power outages from affecting normal work and causing damage to the computer; second, eliminating surges on the mains, instant high voltage, and instantaneous "Power pollution" such as low voltage, wire noise, and frequency offset improves the power quality and provides high-quality power for computer systems.

From the basic application principle, UPS is a kind of power protection equipment that contains energy storage device, with inverter as the main component, and stabilized frequency and stable output.

1) Rectifier: A rectifier is a rectifying device. In short, it is a device that converts alternating current (AC) into direct current (DC). It has two main functions: first, it converts alternating current (AC) into direct current (DC) and supplies it to the load after filtering, or to the inverter; second, it provides the charging voltage to the battery. Therefore, it also functions as a charger;

2) Storage battery: The storage battery is a device used by UPS to store electrical energy. It is composed of several batteries connected in series. Its capacity determines the time for which it maintains discharge (power supply).

3) Inverter: Generally speaking, an inverter is a device that converts direct current (DC) into alternating current (AC). It consists of inverter bridge, control logic and filter circuit;

4) Static switch: Static switch is also called static switch. It is a non-contact switch. It is an AC switch composed of two SCRs connected in antiparallel. control. Divided into two types of conversion and parallel models.

The voltage stabilizer is stabilized by the bounce of the relay. When the grid voltage fluctuates slightly, or other appliances are opened or closed within a certain range, it will cause the automatic correction circuit of the power regulator to start, causing the relay to jump frequently.

Regulator considerations

Daily attention of regulator

1. Avoid violent vibration, prevent the inflow of corrosive gases and liquids, prevent irrigation and place in a ventilated and dry place. Do not cover the fabric to hinder ventilation and heat dissipation.

2. Please use a three-prong (grounded) socket. The grounding screw on the machine must be properly grounded. Otherwise, the case will be charged with a stylus, which is caused by the distributed capacitance induced electricity. It is normal and can be connected through the grounding wire. eliminate. If the case is seriously leaking, and the insulation resistance is less than 2M, it may be that the insulation layer has been wet or the line is short-circuited to the case. You should find out the cause before using the fault.

3, 0.5 1.5KVA low power regulator uses fuse for over-current short circuit protection, 2 40KVA regulator acts as DZ47 circuit breaker for over current and short circuit protection, such as the fuse is often blown or the circuit breaker is often tripped, Check if the power consumption is excessive.

4. When the output voltage exceeds the protection value (the phase voltage protection value is adjusted to 250V ± 5V when leaving the factory), the stabilized power supply automatically protects and cuts off the output voltage of the stabilized power supply. At the same time, the overvoltage indicator lights up. The user should immediately shut down and check the grid voltage or Voltage stabilization. If the voltage regulator is automatically powered off (with input and no output), check whether the mains voltage is higher than 28OV. If it is lower than 280V, check the regulator for failure. Use it after finding out the cause.

5. If the output voltage of the voltage regulator deviates more than 220V, please adjust the potentiometer on the control board until the output voltage is normal.

6. When the mains voltage is often at the lower limit (<150V) or upper limit (> 260V) of the input voltage of the regulator, the limit micro-switch is often touched, which is prone to control failure. At this time, the voltage regulator cannot be adjusted or can only be adjusted up (or can only be adjusted down). You should first check whether the micro switch is damaged.

7. Please keep the inside of the machine clean. Dust will hinder the rotation of the gear and affect the accuracy of the output voltage. Please clean and maintain the coil contact surface in time. When the carbon brush is worn out, the pressure should be adjusted to prevent the brush and coil contact surface from flashing. Carbon brushes should be replaced if the length is less than 2mm. When the coil plane flashes and is burnt black, it should be polished with fine sandpaper.

The input terminal of the three-phase voltage regulator must be connected to the neutral (neutral) line, otherwise the voltage regulator will not work properly and will damage the voltage regulator and electrical equipment. Never use the ground wire instead of the neutral wire (but the neutral wire can be connected in parallel). The neutral wire must not be connected to the fuse.

9. When the output voltage of the voltage regulator is lower than the rated voltage (220V or three-phase 380V), check whether the input voltage is too low. When the rated voltage is reached at no load and the output is lower than the rated voltage at load, this is because the input line load surface is too small, or the load end exceeds the rated capacity range of the regulator, the line voltage drop is too large under load, and the input voltage is lower than Lower limit of the regulator adjustment range. At this time, you should replace the thicker input wire or increase the product capacity.

10. When the power of a single load is large (such as air conditioners, etc.) and the input line is long and the load surface is insufficient, the voltage of the load is severely reduced during the load operation, and it may be difficult to start using the load; when the load is temporarily stopped, it is easy to occur The output is momentarily over-voltage and power-off. If this phenomenon occurs, it is not a failure of the voltage regulator. The input line should be improved (the line is thickened, and the length of the input line should be shortened as much as possible to reduce the voltage drop in the line).

11. When the output voltage of the voltage regulator deviates significantly from 220V, check whether the input voltage is within the voltage regulation range; whether the motor gear is severely worn and the rotation is flexible; whether the limit switch is damaged: whether the coil plane is smooth; Whether the control board is damaged

Regulator Safety Issues

When the stabilized power supply is powered on, do not disassemble the stabilized power supply or pull the input and output wiring of the stabilized power supply at will to prevent electric shock or other electrical safety accidents.

The input and output wiring of the regulated power supply must be reasonably arranged to prevent stepping and abrasion, which may cause leakage accidents.

The stabilized voltage power supply must be reliably grounded. The user is responsible for the electric shock or personal injury caused by the ungrounded line operation.

The ground wire of the stabilized power supply must not be connected to public welfare facilities such as heating pipes, water supply pipes, and gas pipes to avoid infringing the rights of third parties or causing harm.

The input and output wiring of the regulated power supply should be checked regularly to avoid loosening or falling off, which will affect the normal use of the regulated power supply and the safety of power consumption.

The selection of the connection line of the voltage regulator must reach the connection line that can carry sufficient current capacity.

. The voltage stabilizer should be handled gently, avoiding severe vibration when working;

Ensure that the carbon brush spring of the voltage regulator has sufficient pressure to avoid the contact surface of the carbon brush and the coil from flashing;

Non-professionals, please do not disassemble or repair the regulated power supply.

How voltage regulators work

Above 400KVA

Below 400KVA schematic diagram

Because some electrical appliances contain coil components, eddy currents that hinder current will be generated in the early stage of energization. The generation of eddy currents will not only weaken the instantaneous voltage when the appliance is started, resulting in slow startup, but also strengthen the instantaneous voltage generated after disconnection, which may cause spark damage. Circuit. At this time, a voltage regulator is needed to protect the normal operation of the circuit.

The voltage regulator is composed of a voltage regulator circuit, a control circuit, and a servo motor. When the input voltage or load changes, the control circuit samples, compares, and amplifies, and then drives the servo motor to rotate, so that the position of the carbon brush of the voltage regulator changes. By automatically adjusting the turns ratio of the coil, the output voltage is kept stable. Large-capacity regulators also work on the principle of voltage compensation.

Regulator Failure Analysis

Failure performance, cause analysis, summary and elimination

No output, no voltage indication, or no start at startup

Over-voltage or under-voltage protection 1, adjust the internal output voltage adjustable potentiometer

Wrong phase and lack of phase protection 2, three-phase arbitrarily swap two phases

The main control circuit board is broken 3.Replace

Output AC is broken 4.Replace

The output voltage is abnormal

Is a coherent regulator 1, replace the shunt regulator

Exceed the voltage regulator's own voltage regulation range 2. Replace the wide-range voltage regulator

Stroke limit switch is broken 3.Replace

Phase circuit board is broken 4. Replace

Servo motor burned out 5.Replace

Unsteady

Exceed the voltage regulator range of the regulator itself (replace the wide-range regulator)

Stroke limit switch is broken (replace)

The circuit board is broken (replace)

Servo motor burned out (replaced)

Trip for no reason at work

The total capacity of the gate is small (replace the air switch with the proper capacity)

Air switch is broken (replace)

The surge voltage is too high momentarily (replace non-contact high-precision voltage regulator)

Loud buzzing sound inside regulator

overloaded (reduced equipment)

There are debris inside (remove debris)

Voltage regulator abnormal

Voltage instability 1, normal

The carbon brush has dirt on the surface 2. Remove the dirt, call after power failure

Regulator does not run automatically

Fully automatic toggle switch is not turned on 1.

Circuit board failure 2.Replace

Press panel abnormal voltage

(Not available for non-power regulators)

Servo motor burned out 1.Replace

Stroke limit switch is broken 2.Replace

The circuit board is burned out 3.Replace

Manual, automatic knob is not turned to manual 4, open to manual

Friendly Tips: If the regulator fails, you can't rule it out, and you can't stop supplying power to the back-end equipment; please contact the professional company.

Regulator repair introduction

The general maintenance inspection items of the voltage regulator are as follows:

Whether the voltage regulator still has design and installation defects;

Check whether the load current and operating voltage of the regulator are normal;

Check whether there is oil leakage in the regulator, whether the oil level, oil color, and temperature exceed the allowable values. The upper oil temperature of the oil-immersed self-cooled regulator is generally below 85 ° C. The pressure should be below 75 ;

Check whether the high and low voltage porcelain bushings of the voltage regulator are clean and there are no cracks, breakage and flashover discharge marks;

Check the terminals of the voltage regulator for poor contact and overheating;

Check whether the operating sound of the voltage regulator is normal; there is a uniform humming electromagnetic sound during normal operation. If there is a crackling discharge sound inside, it may be a breakdown of the winding insulation. If an uneven electromagnetic sound occurs, it may be iron The core threaded bolt or nut is loose.

Check whether the hygroscopic agent of the voltage stabilizer reaches the saturation state;

Check whether the oil cut-off door of the voltage regulator is normal, and whether the cut-off door to the gas relay and the radiator are open;

Check whether the diaphragm of the explosion-proof tube of the voltage stabilizer is complete, and whether the diaphragm glass is marked with "ten";

Check whether the cooling device of the voltage regulator is operating normally, whether the temperature of the heat pipe is uniform, and whether the oil pipe is blocked;

Check if the shell of the regulator is well grounded;

Check whether the gas relay is full of oil and no gas exists;

For outdoor voltage regulators, check whether the foundation is good and whether the foundation is sinking. For transformer poles, check whether the poles are firm and whether the poles and poles are decaying.

For indoor voltage stabilizers, focus on checking whether the doors and windows are intact, and check whether the blind wire gauze is complete;

Other items that should be checked.