① Ferroresonance AC voltage regulator. It is composed of a saturated choke and a corresponding capacitor, and has the characteristics of constant voltage and constant current.
② AC voltage regulator of magnetic amplifier. The magnetic amplifier and autotransformer are connected in series, and the output voltage is stabilized by changing the impedance of the magnetic amplifier through electronic circuit.
③ Sliding AC voltage regulator. The output voltage is stabilized by changing the position of sliding contact of transformer.
④ Induction AC voltage regulator. By changing the phase difference between the secondary and primary voltages of the transformer, the output AC voltage is stable.
⑤ Thyristor AC voltage stabilizer. Thyristors are used as power regulating elements. High stability, fast response and no noise. But it causes interference to communication equipment and electronic equipment. After the 1980s, three new types of AC regulated power supplies appeared: compensated AC regulators. Numerical control stepping AC voltage regulator. Purify AC voltage regulator. It has a good isolation function and can eliminate the peak interference from the power grid.
Numerical control stabilized power supply: sampling at the output end of the equipment through the observation area, comparing and checking the current voltage with the rated voltage, and if the comparison result is negative, sending the data to the central processing unit (CPU), and the CPU will issue the command of voltage addition. Meanwhile, the detection area detects whether the semiconductor has been turned on or off. After confirmation, the CPU gives the command of adding voltage to control the semiconductor to work and make it reach the standard of rated voltage. If it is positive, the CPU will give a command to reduce the pressure, and the whole process can be digitized in only 0.048 seconds.
The equipment will stabilize the instantaneous and repeated voltage through the digital control loop to ensure that the output voltage is always the rated voltage.
The digital tap-changing method, which uses the digital control principle to monitor the voltage change and adjust the transformer tap through the electronic crystal gate switch, is also called DC voltage regulator. Its power supply voltage is mostly AC voltage. When the voltage of AC power supply or the voltage of output load resistance changes, the direct output voltage of the regulator can remain stable. The parameters of voltage regulator include voltage stability, ripple coefficient and response speed. The former indicates the influence of input voltage change on output voltage. Ripple coefficient indicates the magnitude of AC component in output voltage under rated working conditions; The latter indicates the time required for the voltage to return to normal when the input voltage or load changes sharply. DC regulated power supply is divided into continuous conduction type and switching type. In the former, the single-phase or three-phase AC voltage is changed to an appropriate value through a power frequency transformer, and then an unstable DC power supply is obtained through rectification and filtering, and then a stable voltage (or current) is obtained through a voltage stabilizing circuit. This kind of power supply has simple circuit, small ripple and small mutual interference, but it is bulky, consumes a lot of materials and has low efficiency (often less than 40% ~ 60%). The latter adjusts the output voltage by changing the on-off time ratio of the regulating element (or switch), so as to achieve the purpose of voltage stabilization. The power consumption of this power supply is small, and the efficiency can reach about 85%, but its disadvantages are large ripple and mutual interference. So it has developed rapidly since the 1980s. From the perspective of working methods, it can be divided into:
① Controllable rectifier type. The output voltage is adjusted by changing the conduction time of the thyristor.
② chopping type. The input is an unstable DC voltage, which can change the switching ratio of the switching circuit to get a unidirectional pulsating DC, and then a stable DC voltage can be obtained through filtering.
③ Converter type. The unstable DC voltage is first converted into high-frequency alternating current by the inverter, and then sampled from the new DC output voltage after transformation, rectification and filtering, and the working frequency of the inverter is controlled by feedback, so as to achieve the purpose of stabilizing the DC output voltage.
Electrical appliance use
AC regulated power supply is applied to the voltage stabilization and protection of modern high-tech products such as computers and their peripheral equipment, medical electronic instruments, communication and broadcasting equipment, industrial electronic equipment and automated production lines. DC regulated power supply is widely used in national defense, scientific research, universities, laboratories, industrial and mining enterprises, electrolysis, electroplating, charging equipment and so on.
(1) can be used for various electronic equipment aging, such as PCB aging, household appliances aging, various IT products aging, CCFL aging, lamps aging, etc.
(2) It is suitable for aging and testing of electronic components that need to be automatically turned on and off at regular intervals and automatically count the number of cycles.
(3) Pulse aging of electrolytic capacitors
(4) Precision testing of resistors, relays and motors.
(5) the whole machine is excellent; Performance test of electronic components, conventional test The so-called inverter regulated power supply is also called variable frequency power supply. The variable frequency power supply is controlled by 16-bit Motorola processor, adopts high frequency PWM design and is driven by imported Mitsubishi 1GBT. The efficiency is above 85%. Quick response, unloading/loading 100%, stable voltage reaction time within 2 ms, strong overload capacity of variable frequency power supply, and instantaneous current can bear 300% rated current. Pure waveform, high frequency and stability, no interference electromagnetic wave (EMI, EMC). Frequency conversion power supply is not only the best power supply for R&D, laboratory and measurement room, but also the standard power supply for EM/EMC/ safety testing.
The variable frequency power supply has the characteristics of strong load adaptability, high efficiency, good stability, good output waveform quality, simple operation, small volume and light weight. For different types of power supply in the world, users can not only simulate their voltage and frequency (47 ~ 63 Hz) for test application; Among them, the intermediate frequency power supply specially designed according to the national military standard can also support the application equipment of national defense military detection, avionics, navigation and communication with 400Hz frequency.
Whether it is purely resistive, capacitive, inductive or nonlinear load, this variable frequency power supply can be used normally for a long time. Three phases can be used for single phase. The voltage and frequency can be adjusted according to the load. Some models can be set with power-on password, which is convenient for safe use in the production workshop. structure
Figure 1 is the schematic diagram and equivalent block diagram of the switching regulated power supply, which consists of a full-wave rectifier, a switching tube V, an excitation signal, a freewheeling diode Vp, an energy storage inductor and a filter capacitor C. In fact, the core part of the switching regulated power supply is a DC transformer.
Inverter is a device that converts DC into AC. Inverters are usually widely used in standby power supply composed of level or battery.
DC converter, which is a device that converts DC into AC, and then converts AC into DC. This device is widely used in switching regulated power supply. DC converters can be used to convert DC power supply voltages into various DC power supply voltages with different polarities and values.
Shared species
Full-automatic compensation power regulator
Basic structure: the motor drives the carbon brush to slide between turns of the autotransformer, and directly adjusts the output voltage or adjusts the output voltage through the compensation transformer.
Advantages: strong load capacity, high working efficiency, small waveform distortion and strong anti-interference ability of power supply itself.
Disadvantages: slow response time (≥ 1S), mechanical wear, requiring regular maintenance, and noise generated by AC contactor and motor during voltage stabilization.
Applications: large electromechanical equipment, metalworking equipment, production lines, construction engineering equipment, elevators, medical devices, embroidery and textile equipment, air conditioning, radio and television, household appliances and lighting in the fields of industry, agriculture, transportation, posts and telecommunications, military affairs, railways, scientific research and culture.
Features:
1, fast response: less than 30ms (better than two power cycles)
2. Powerful purification function: it can filter out the interference of power grid to load and the interference of load to power grid.
3. High voltage stabilization accuracy: 0.5% of rated output voltage.
4. Strong anti-interference ability: it can absorb high-energy pulse interference from external circuits.
5. High efficiency: up to 98.5%.
6. High power factor: it can effectively improve the power factor of the line.
7. Small size: only 25% of the traditional model.
8. Strong overload capability: 5 times the rated current 1 sec.
9. Distortion bottom: Special LC filter circuit can reduce the distortion of output voltage waveform.
10, lightning protection: it has certain lightning protection ability.
Ac purification regulator
Basic structure: the output voltage is adjusted by adjusting the conduction angle of the primary circuit thyristor by combining sine wave energy distribution with filtering.
Advantages: high voltage stabilization accuracy ≤ 65438 0%, fast response time ≤40ms, and sharp pulse filtering function.
Disadvantages: There is a phase shift between the output and the input voltage, a little waveform distortion (additional ≤3.5%) and some special loads (such as SCR loads) are not ideal.
Applications: precision electronic equipment, medical equipment, computer room, laboratory, product aging and testing.
Contactless AC voltage regulator
Basic structure: By switching one or more groups of thyristors when the voltage or current crosses zero, the compensation winding of one or more transformers in the compensation transformer group will step up and down, the primary circuit will be short-circuited, or the tap of autotransformer will be switched to adjust the output voltage.
Advantages: strong load capacity, high working efficiency, small waveform distortion, fast response time and low noise.
Disadvantages: the voltage stabilization accuracy is not high.
Application: All the places that need voltage stabilization.
Basic structure of parameter regulator
The output voltage is basically stable by using the saturation characteristics of iron core materials.
Advantages: reliable operation, strong overload capability, automatic protection when the output is short-circuited, simple structure, wide voltage stabilizing range and strong anti-interference capability.
Disadvantages: heavy weight, large volume, high price, high noise, rising core temperature, and high requirements for the working frequency of input power supply.
Application fields: computer-related products, medical monitoring systems, program-controlled systems, automatic test equipment, radio and television equipment, post and telecommunications equipment, automatic plug-in machines, production lines, printing equipment, injection molding equipment, ATM, SMT equipment, scientific research experiments, etc.
Basic structure of magnetic amplifier AC voltage regulator
The output voltage is stabilized by changing the reluctance of the magnetic amplifier transformer connected in series with the primary circuit of the autotransformer.
Advantages: high voltage stabilizing accuracy and fast response time.
Disadvantages: heavy weight, large volume and high price.
Applications: precision electronic equipment, medical equipment, computer room, laboratory, product aging and testing.