Circuit board for power inverter
A circuit that inverts a dc current into an alternating current is called an inverter circuit.Under certain conditions, the same thyristor converter circuit can be used as both rectifier and inverter.
When the converter is working in the inverter state, if the converter's ac side is connected to the ac power supply, the dc inverter is transformed into the ac power of the same frequency and sent back to the grid, called active inverter.If the ac side of the converter is not connected to the grid, but directly connected to the load, that is, the dc inverter is changed to a certain frequency or adjustable frequency ac supply load, then it is called passive inverter.Ac frequency control is based on this principle.Active inverter is not only used in dc reversible speed control system, but also used in series speed control and HVDC transmission of ac rv asynchronous motor.
|The method of converting alternating current to direct current is rectification.The method of converting dc to ac is inverter.|
Rectifier, full-wave rectifier circuit is the use of the characteristics of the diode to the single, with four diodes into a bridge rectifier circuit (see chart), make the input is alternating current, the waveform is sine wave, is alternating current direction, and the output waveform current into the same direction, through the filter circuit will direct current can be obtained after the wave filter out.
|The source inversion also has the source inversion.For example, if the dc voltage goes through a simple single-phase h-type thyristor bridge, the horizontal of H is that output. There are four thyristors on the vertical line of H, no. 12 and no. 34, respectively turn on 14 and 23 to get the output voltage and current separated by positive and negative.|
Application of pulse width modulation in inverter power supply
The basic square wave inverter is simple, but the harmonic content of output voltage waveform is too large, and THD (current harmonic distortion rate) is too large.The harmonic content of the output voltage waveform of the phase-shifting multiple superposition inverter is small, i.e., THD is small, but the circuit is more complicated.PWM PWM pulse width modulation inverter power supply, which has both computer circuit and output voltage waveform, has been widely used
Inverter without dc input
Such faults often occur because the battery is not properly connected. The positive and negative poles of the inverter must be correctly connected with the battery, the positive and negative poles are connected correctly, and the negative poles are connected correctly.
The inverter fuses out and in
This kind of fault can be seen clearly generally, as long as the replacement fuse can
The battery voltage is 20% higher than the rated dc input voltage
The inverter has a working voltage range, which is generally rated between +-10% dc voltage. If the voltage is higher than that, the battery pack or inverter shall be replaced to prevent damage to the machine.
The battery voltage is 15% below the rated dc input voltage
This kind of problem is mainly because the battery power is insufficient, only needs to charge the battery.
Excessive load power
This kind of problem is mainly caused by insufficient calculation of load power at the earlier stage, which requires either increasing the power of the inverter or reducing the load power.