Scientific selection of frequency converter is crucial to the normal operation of frequency conversion system。 A lot of beginners to the general inverter selection method understanding is not enough, or even if you know the method, but also not sure whether the choice of the inverter model is the right solution, the following small an for everyone to solve the mystery。
The selection of frequency converter should first look at the ac motor. Because the frequency conversion system generally determines the motor, and then choose the inverter. In principle, the type of frequency converter shall be determined according to the actual current of ac when working for a long time, instead of the power on the motor nameplate.
The type selection of frequency converter depends on the type of load. The load equipment driven by the frequency conversion system can be roughly divided into three types: constant torque load, constant power load, fan and pump load. Different types of load choose different types of frequency converter.
1. Constant power load
During the operation of the load equipment, the power is kept constant。 Such as machine tools, cutting machines, paper machines and so on。
For example: a marble cutting machine frequency conversion system, is a constant power load, load inertia is very large, the frequency converter type configuration AMB300 with the same power G machine, plus the brake unit and brake resistance。
2. Constant torque load
Constant torque load equipment requires converter low frequency torque, dynamic response speed。 AMB inverter can reach 150% torque in 0HZ vector state, which can meet the needs of various working conditions。
For example: a dredger bucket inverter system, is a constant torque load, double motors, and the load overload time is long, so the inverter model selection configuration AMB300 amplifier two gear G parallel machine, at the same time the power supply of the equipment for the generator power supply, the inverter needs to configure input ac reactor.
3. Fan and pump loads
This is the most suitable for the field environment with frequency conversion speed regulation, there is no too high requirements for the inverter function technology, the use of ambition inverter energy saving effect is significant。
For example, the frequency conversion system of a large central heating equipment in northeast China, in which the blower, induced fan (centrifugal fan) inverter is configured with p-type machine of the same power; Refill pump (centrifugal pump) inverter type P machine with the same power; Type G machine with the same power; Belt conveyor (coal conveyor) inverter type selection and configuration of a g-type machine; The frequency converter of slag-removing machine is configured with a g-type machine with a first gear amplifier. Crusher (coal crusher) inverter selection and configuration of amplifying one or two gear G machine.