Does the inverter need to add line and outlet reactors?
These auxiliary devices must be configured for inverters with large power outputs. Different manufacturers have detailed instructions in the user guide.
Let’s take a preliminary look at the role of the “AC input reactor” installed at the input of the inverter. It is mainly to improve the power factor of the AC power on the AC side of the input side; effectively eliminate the higher harmonics on the input side and prevent voltage distortion. Causes damage to other electrical equipment; eliminates input current imbalance due to imbalance between three-phase AC power.
Generally, when adding an AC input reactor, an “EMC input filter” is added to the input side of the inverter, which is mainly to minimize the external conduction and radiation of the inverter itself;
The domestically-made inverter basically has an inverter with a capacity of 37kw (50HP), a power input capacity of 114kvA, an input current of 157A, and an output current of 150A or more. All of them are equipped with external DC reactors, which are configured according to different powers. The type of DC reactor needs to be adapted.
The user needs to remove the short-circuit copper bus between the main circuit terminal P and (+) of the inverter during installation, and then connect the DC reactor between P and (+), the reactor terminal and the inverter. There is no polarity between terminals O(+). After the DC reactor is installed, the short-circuit copper bar between P and (+) is no longer used.
The DC reactor is connected in series between the rectifier module and the filter capacitor inside the inverter. Its function is to improve the power factor of the input side; improve the overall efficiency and thermal temperature of the inverter; effectively eliminate the influence of the higher harmonics on the input side on the inverter, and reduce the external conduction and radiated electromagnetic interference of the inverter itself.
“AC reactors” are installed between the output side of the inverter and the drive motor, close to the inverter. Its main function is to filter, suppress the inrush current of the input side circuit, and weaken the influence of the imbalance of the power supply voltage on the overcurrent caused by the inverter; generally, the distance between the inverter and the motor is more than 100 meters. It is recommended to install an output AC reactor. Because the output side of the inverter generally contains more high-order harmonics. When the motor is far away from the inverter, because there is a large distributed capacitance in the cable, one of the harmonics may resonate in the loop, which will cause great damage to the insulation performance of the motor. Damage to the motor. In addition, due to the long line, a large leakage current will be generated, which will cause frequent shutdown and shutdown of the inverter.