Single-phase 220V to three-phase 380V boost inverter

First, the market demand

Due to national policies and regional restrictions, many regions will now withdraw three-phase 380V industrial power, and the cumbersome procedures for applying three-phase electricity in areas without three-phase electricity, various labor costs, and various hidden costs, etc., lead to some The region cannot use industrial 380V electricity, and general industrial equipment, such as motors, are mostly three-phase 380V. In the absence of three-phase electricity, it can not be operated. Only a way to convert single-phase 220V into three-phase 380V, but Many single-phase 220V electric three-phase 380V equipment on the market are expensive and outrageous, which makes many users in need have to be discouraged. The original machine can only be temporarily placed or placed in other places with industrial power.

Now we are introducing a single-phase 220V input to three-phase 380V output inverter, which can drive the three-phase asynchronous motor to start soft start and stepless speed regulation. Input power only needs single-phase 220V, output three-phase 380V, and most users can accept the price. It is about 1/10 of the price of the booster on the market. It is small in size and powerful in function. 0-650Hz can be adjusted freely. Solve the embarrassing situation that industrial equipment does not have three-phase electricity.

Second, the principle and characteristics of 220V to 380V inverter

The principle of the frequency converter is to apply the principle of frequency conversion technology and microelectronic technology. The power control equipment of the AC motor is controlled by changing the frequency of the working power of the motor, and the power frequency alternating current with constant voltage and frequency is converted into voltage or frequency. The device of alternating current is called "inverter".

The waveform outputted by the inverter is an analog sine wave, which is mainly used for three-phase asynchronous motor speed regulation, also called frequency converter. The frequency converter is mainly composed of rectification (AC to DC), filtering, inverter (DC to AC), braking unit, drive unit, and detection unit micro processing unit. The frequency converter mainly adopts the AC-DC-AC mode (VVVF frequency conversion or vector control frequency conversion). First, the power frequency AC power supply is converted into a DC power source through a rectifier, and then the DC power source is converted into an AC power source whose frequency and voltage can be controlled to supply. electric motor.

The 220V to 380V inverter converts the power frequency AC 220V power supply into a DC power supply through a rectifier (double voltage rectification), and then converts the DC power into a three-phase 380V AC power source whose frequency and voltage can be controlled to supply the motor.

2.1 inverter function

1. It can reduce the impact on the power grid, and it will not cause the problem of excessive peak-to-valley difference.

2. The acceleration function can be controlled to smoothly accelerate according to the needs of the user;

3. The motor and equipment stop mode can be controlled, making the whole equipment and system more secure and the life expectancy will increase accordingly;

4. Control the starting current of the motor, fully reduce the starting current, and reduce the maintenance cost of the motor;

5. It can reduce the wear of mechanical transmission components, thereby reducing procurement costs and improving system stability.

6. Reduced motor starting current, providing a more reliable variable voltage and frequency.

7. Effectively reduce reactive power loss and increase the active power of the grid

8. Optimize the process and change rapidly according to the process. It can also realize the speed change through remote control PLC or other controllers.

Third, product features

The single-phase 220V variable three-phase 380V inverter adopts the AC-DC-AC circuit structure, and uses the SPWM modulation control technology to convert the ordinary single-phase 220V electric power into the industrial three-phase 380V electric power. Applicable to three-phase asynchronous motor, the output phase angle is 120°, fully meets the motor use standard, and is suitable for various types of motor loads. The single-phase electric-to-three-phase electric inverter solves the inconvenience caused by three-phase electric power limitation in some areas, and also solves some users' demands that cannot be applied for three-phase electric power due to site restrictions.

3.1 Technical characteristics:

· Ordinary mains 220V input, eliminating the cumbersome procedures for applying for three-phase electricity and various labor costs and various hidden costs

·The output uses industrial three-phase electricity, but it is economical according to civil single-phase electricity billing.

·The core components are imported devices with stable performance and long service life.

·Safe and reliable, the input single-phase electricity is completely electrically isolated from the output three-phase electricity

·Input wide pressure range design, adapt to the working environment of low commons voltage in all regions

·The output protection function is perfect, and there are various protections such as overvoltage, overload, over temperature, short circuit and over current.

Fourth, the inverter installation environment requirements

4.1 Electrical use conditions Prevent electromagnetic interference. Due to the rectification and frequency conversion, the inverter generates a lot of interference electromagnetic waves around the inverter. These high-frequency electromagnetic waves have certain interference to nearby instruments and instruments. Therefore, the instrument and electronic system in the cabinet should use a metal casing to shield the inverter from interference with the instrument. All components should be grounded reliably. In addition, shielded control cables should be used for wiring between electrical components, instruments and meters, and the shielding layer should be grounded. If the electromagnetic interference is not handled well, the whole system will not work, resulting in failure or damage of the control unit.

4.2 Ambient temperature: The ambient temperature of the inverter refers to the temperature near the cross section of the inverter. Since the frequency converter is mainly composed of high-power power electronic equipment that is highly susceptible to temperature, the life and reliability of the inverter depend largely on the temperature, which is generally -10 °C to +40 °C. In addition, it is necessary to consider the heat dissipation of the inverter itself and the extreme conditions that may occur in the surrounding environment. There is a certain margin for the temperature.

4.3 Ambient humidity: The inverter requires no more than 90% relative humidity to the surrounding environment (no condensation on the surface).

Vibration and shock: During the installation and operation of the inverter, care should be taken to avoid vibration and shock. In order to avoid the solder joints and loose parts of the internal components of the inverter, causing serious electrical failure or even short circuit and other serious faults. Therefore, the vibration acceleration of the installation site is usually limited to 0.6 g or less, and special earthquake resistance measures such as anti-vibration rubber can be added in special places.

4.4 Installation site: The maximum allowable output current and voltage of the inverter are affected by its heat dissipation capability. When the altitude exceeds 1000 m, the heat dissipation capacity of the inverter will decrease. Therefore, the inverter is generally required to be installed at an altitude of 1000 m or less. Abnormal environmental conditions, such as exposure to excessive dust, altitude >1000 m, etc., require special selection. Structure or protective components.

4.5 Inverter storage: In actual application, the inverter is usually installed on the site or installed nearby. If the site environment is poor (high temperature, humidity, dust), the inverter can be placed under the conditions allowed by the operation. Electric control room. When the operator is placed on site, for the safety of the inverter, the general ambient temperature should be -10 ° C ~ +50 ° C. When used in the open air, such as oil fields, offshore oil wells, mines, etc., the temperature in winter should be lower than -10 °C, can be heated by electric heater, the inverter is placed in the external box; when the summer temperature is higher than +50 °C, the ventilation can be strengthened, or An insulating coating is applied to the outside of the box to reduce radiation and heat transfer. According to the actual situation on the spot, according to local conditions, people try to improve the environment and ensure safety. For the harsh environment where dust, fiber, etc. exist on the site, the inverter should be placed in the box, and a filter should be installed at the inlet and outlet to clean and strengthen the maintenance regularly.

Fifth,Projects that the inverter regularly checks

5.1 Fresh replacement of the filter

· Generally with the equipment with a set of spare filters, the filter can be washed.

· Daily cleaning, keep the floor clean

·Replacement after long-term use

5.2 fastening bolts

5.3 dust removal

· Perform a cleaning treatment on the inside of the main control box for about half a year to check whether the circuit board is loose and whether the small fan can rotate flexibly.

· Perform a comprehensive cleaning treatment on the inverter for about half a year.

High-pressure ceramic bottles, insulators, voltage divider resistors, lightning arresters and other high-voltage equipment also need to be cleaned regularly.

5.4 ventilation and heat dissipation

· When the summer ambient temperature is high, the ventilation of the inverter installation site should be strengthened to ensure good ventilation and heat dissipation conditions of the inverter.

·If the inverter resumes operation after shutdown, if the environment is wet, please turn on the control power supply first, so that the inverter is ventilated for half an hour to drive out the internal moisture of the inverter, and then put it into operation with high voltage.

Six, solve problems and precautions

6.1 solve the problem:

·Boost inverter input single-phase 220V drive can soft start the three-phase 380V asynchronous motor, no industrial three-phase 380V electric drive

· The boost inverter output phase angle is 120°, which fully meets the motor use standard and is suitable for various types of motor loads.

·Boost inverter input frequency 50/60HZ, output frequency adjustable 0-650HZ

6.2 Note:

·Boost converter is a capacitor booster. For the light load type of 22kw or less for load, in the selection, the light-loaded motor uses a large-scale inverter, and the heavy-loaded field selects a large-level one. Inverter.

· The boost converter can only be used in three-phase asynchronous motors and cannot be used as a power source.

• Boost converters are not suitable for applications that require fast start and stop, and where there is a potential load.