Inverter main circuit wiring
A: the main circuit power supply side of the junction
The 1 circuit breaker
In the three-phase AC power supply and power supply terminals ( R, S, T ), need to access for inverter power circuit breaker ( MCCB ). Breaker capacity chosen for the rated current of the 1.5-2 times between.
The 2 electromagnetic contactor
In order to be able to in the event of a system failure, effectively cutting off the power converter input, can be used in the input side mounted electromagnetic contactor control main circuit power off, in order to ensure safety.
The 3 input AC reactor
In order to prevent the power grid peak pulse input, large current flows into the input power supply circuit and rectifier components and damage on the input side, need to access the AC reactor, but also can improve the input power factor. In order to ensure the effective use of transducer, proposal 80V converter 110KW ( including) above with input reactor, 220V grade 45KW ( including) above with input reactor.
The 4 input side noise filter
The use of frequency converter, likely through power line interference inverter around other electronic equipment, the use of filter can reduce the peripheral equipment interference.
Two : the main circuit of inverter side of the junction
1 DC reactor
DC reactor can improve the power factor, can be avoided due to the access of large capacity transformer and inverter access current is too large to rectifier bridge damage, can avoid the voltage mutation or phased relative to the load caused by harmonics on rectifying circuit damage.
The 2 braking unit and brake resistor
YT800 series ( 380V grade ) converter in 11KW and the following models with built-in braking unit, in order to release the brake feedback energy, must be in the P, PB connected braking unit. One should note that:
Braking resistor wiring length of less than 5M, braking resistor for releasing energy temperature is high, the installation of braking resistor should be safety first protection and good ventilation. The need for an external braking unit, braking unit P, P - terminal is respectively connected with the frequency converter of P +, P - terminal one one correspond, in the brake unit of BR1, BR2 connected braking resistor. At the same time power frequency converter of P +, P - end and the braking unit of P +, P - terminal connection should be less than 5 meters, the brake unit BR1, BR2 and braking resistor wiring length should be less than 10 meters.
Also note that: P +, P - class, not to engage in reverse; P +, P - terminal does not allow direct braking resistor, otherwise it will damage the transducer or a fire hazard.
Three : the main circuit the motor side of the connecting
The 1 output reactor
When the inverter and the motor of the distance between the more than 50 meters, the factory cable on the parasitic capacitance effects lead to leakage current is too large, easy to occur frequently converter over-current protection, because in order to avoid the motor insulation damage, must add output reactance.
The 2 output side noise filter
Increase the output noise filter can reduce the frequency converter and motor between cable caused by radio noise and lead leakage current.
Four: ground connection ( PE )
In order to ensure the security, protection against electric shock and fire accidents, inverter grounding terminal PE must be well connected with the grounding, grounding resistance less than 10 ohm. Grounding wire should be thick and short, should use above 3.5mm2 stranded copper core wire. Multiple frequency grounding, suggested that do not use a common ground, to avoid grounding wire feed circuit.
Five: RBU series of energy feedback unit connection
RBU series of energy feedback unit can be in regenerative braking of motor power of feedback network. RBU series of energy feedback unit using IGBT as rectifying feedback, compared to the traditional three opposite parallel bridge type rectifier unit, feedback filter distortion component is less than the fundamental wave of 4%, little pollution to power grid. Feedback unit is widely used in oil pumping machine, centrifuge, hoist equipment.
Six: Common DC bus connection
In the paper making machinery, chemical fiber multi motor drive applications, generally uses the DC bus scheme. Some moment, some motor in an electric state, while some other motor is in the regenerative braking state ( power ). The renewable energy in linear bus automatic balance, can supply electric state when the motor is used, thereby reducing the entire system from power absorption power, achieve the purpose of energy saving.
When the two motors work simultaneously when working, one of them will always be in the regenerative braking state, another one is always in a state of electric. The two inverter DC bus in parallel, regenerated power supply electric state of the motor, thereby achieving the purpose of energy saving.
The above is the converter connection, these information to help, country hair electrical switch factory offers, www.jiandq.com 15957745520