Voltage regulator: it is a kind of power supply circuit or power supply equipment that can automatically adjust the output voltage, and its function is to stabilize the power supply voltage that fluctuates greatly and fails to meet the requirements of electrical equipment within its set value, so that all kinds of circuits or electrical equipment can work normally under the rated working voltage.
Voltage regulator: large tens to thousands of watts of AC voltage regulator, is the supply of large-scale experiments and industrial, medical equipment, power supply. There are also small a few watts to a few kilowatts of AC voltage regulator, is to provide high quality power supply for small laboratory or home appliances,
The initial power regulator is to rely on the jump of the relay to stabilize the voltage. When the grid voltage fluctuates, the power regulator's auto-correct circuit activates, causing the internal relay to operate. Forcing the output voltage to remain near the set value, the advantage of this circuit is a simple circuit, the disadvantage is that the accuracy of voltage stabilization is not high and every time the relay jumps to shift, will make the power supply occurs a transient interruption and produce sparks interference.
This is a great interference to the reading and writing of the computer equipment, which can easily cause the computer to have wrong signals, and in serious cases, the hard disk will be damaged.
Now high-quality small voltage regulator, most of the motor drag the carbon brush method of stabilizing the voltage, this regulator on the electrical equipment produced by the interference is very small voltage regulator accuracy is relatively high. Because some electrical appliances contain coil components, in the initial period of energization will produce an obstacle to the current eddy current, eddy current generation will not only weaken to the electrical appliances start-up transient voltage, resulting in slow start-up, but also strengthen the transient voltage generated after the circuit breaker, may produce sparks damage circuit. At this point, a voltage regulator is needed to protect the normal operation of the circuit.
Voltage regulator by the regulator circuit, control circuit, and servo motors, etc., when the input voltage or load changes, the control circuit for sampling, comparison, amplification, and then drive the servo motor rotation, so that the regulator carbon brushes to change the position of the coil turns by automatically adjusting the ratio to maintain the stability of the output voltage. Larger capacity regulator, but also use the principle of voltage compensation work. With the rapid advance of society, electricity equipment is increasing day by day. But the aging of power transmission and distribution facilities and the development of lagging, as well as poor design and inadequate power supply and other reasons resulting in the end of the user voltage is too low, while the head of the line users are often high voltage, the power equipment, especially on the voltage requirements of strict high-tech and precision equipment, unique as an untimely bomb. The utility system as a public **** power grid, connected to thousands of various loads, some of the larger inductive, capacitive, switching power supply and other loads not only from the grid to obtain electricity, but also in turn on the grid itself, deterioration of the power grid or local power supply quality of the grid, resulting in utility voltage waveform distortion or frequency drift. In addition unexpected natural and man-made accidents, such as earthquakes, lightning strikes, transmission and substation system breaks or short circuits, can jeopardize the normal supply of electricity, thus affecting the normal work of the load.
Unstable voltage can cause fatal injuries or malfunction of equipment, affecting production and resulting in delayed delivery, unstable quality and other aspects of loss. At the same time accelerate the aging of the equipment, affecting the service life or even burn accessories, so that owners face the need to repair the trouble or short-term need to update the equipment, a waste of resources; serious or even safety accidents, resulting in incalculable losses.
According to the test of the power experts, the grid often occurs and the computer and precision instruments to produce interference or damage to the problem are mainly the following:
1, power surge (power surges): refers to the output voltage RMS value is higher than the rated value of 110%, and the duration of one or several cycles. Power surges are mainly due to large electrical equipment connected to the power grid shutdown, the grid due to sudden unloading of high voltage.
2, high-voltage spike pulse (high voltage spikes): refers to the peak value of 6000v, the duration from one ten thousandth of a second to one-half cycle (10ms) of the voltage. This is mainly due to lightning strikes, arc discharges, static discharges or switching operations of large electrical equipment.
3, transient over-voltage (switching transients): refers to the peak voltage of up to 20000V, but the duration of the boundaries of millionths of a second to ten thousandths of a second of the pulse voltage. Its main reason and may cause damage similar to the high-voltage spike pulse, just in the solution will be different.
4, voltage sag (power sags): the utility voltage RMS value between 80% and 85% of the rated value of the low-voltage state, and the duration of one to several cycles. Large equipment start-up, large motor start-up, or large power transformer access can cause this problem.
5, electrical line noise (electrical line noise): refers to radio frequency interference (RFI) and electromagnetic interference (EFI) and a variety of other high-frequency interference. Motor operation, relay action, motor controller work, radio transmission, microwave radiation, and electrical storms, etc., will cause line noise interference.
6, frequency offset (frequency variation): refers to the change in utility frequency more than 3Hz. This is mainly by the unstable operation of the emergency generator, or by the frequency of unstable power supply.
So the use of voltage stabilizers, power equipment, especially on the voltage requirements of strict high-tech and precision equipment is essential. Item single-phase three-phase (three-phase four-wire system, sub-regulation)
Voltage regulator input voltage range 160V ~ 250V Phase voltage 160V ~ 250V
Line voltage 280V ~ 430V
Voltage regulator output voltage 220V or 110V Phase voltage 220V Line voltage 380V
Voltage regulator overvoltage protection value 246V±4V Phase voltage 246V±4V (subject to phase voltage)
Line voltage 426V
Voltage regulator voltage accuracy ±3%
A. The regulator has an input voltage adaptation range. the IEC standard for the input voltage in the rated value of the ± 10 range. Out of the range of the automatic sound and light alarm and can not make the output voltage stabilized in the required range.
B. Output Voltage Adjustment Rate, is the effect of changes in the input voltage caused by changes in the output, when the load for the rated value, the input voltage according to the source voltage range from the rated value up to the upper limit and to the lower limit, the maximum change in the output voltage is measured (±). The smaller the value, the better, is an important indicator of the performance of AC voltage regulator.
C. Load Adjustment Rate: is the effect of changes in the load caused by changes in the output. Change the load current size, measure the output voltage change (±). The smaller the value, the better, but also an important indicator of the performance of AC voltage regulator.
D. Output voltage relative harmonic content (also known as output voltage distortion), usually expressed in THD, is the harmonic content of the total RMS and fundamental RMS ratio, when the load for the rated value, the input voltage distortion to meet the baseline conditions (generally should be less than 3), in the input voltage for the lowest, rated value and the highest value of the measurement of the output voltage distortion, and take the largest. The smaller the value, the better.
E. Efficiency: is the output active power P0 and input active power Pi ratio (percentage),
F. Load power factor
Voltage regulator capacity with volt-ampere (VA) or kilovolt-ampere (KVA) value, is the load in addition to the purely resistive loads, there are also inductive and capacitive loads, i.e., in addition to the load in the active power, there is reactive power. This pointer reflects the ability of the AC voltage regulator to carry inductive and capacitive loads.
General AC regulated power supply, load power factor cosφ is 0.8, when the product is 1KW, the output active power (i.e., with resistive loads) maximum 800W. if the product is expressed in 1KW (cos φ is still 0.8), the output active power of 1KW, which can be output power S=1000 / 0.8 = 1250VA. load power When the value of the load power factor is small, it means that the power equipment has a stronger ability to adapt to the resistive load.
G. AC voltage regulator parameters and 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 that the larger the better, the maximum of 1), the relative harmonic content of the source current, audio noise, etc., three-phase AC regulated power supply, and the three-phase output voltage imbalance, etc., the definition and test method can refer to the relevant standards. Definition and test method of these pointers can refer to the relevant standards. Voltage regulator can be widely used in: industrial and mining enterprises, oil fields, railroads, construction sites, schools, hospitals, post and telecommunications, hotels, scientific research and other departments of electronic computers, precision machine tools, computed tomography (CT), precision instruments, test equipment, elevator lighting, imported equipment and production lines and other places that require power supply stable voltage. Also adapted to the power supply voltage is too low or too high, the fluctuation amplitude of the end of the low-voltage distribution network users and load changes in the power equipment, especially for all the power grid waveform requirements of high voltage stabilization of power places. High-power compensated power regulator can be connected to thermal, hydraulic, small generators.