Beijing Leader & Harvest Electric Technologies Co., Ltd.

Variable Frequency Drive

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A Variable Frequency Drive

A Variable Frequency Drive
Variable Frequency Drive for asynchronous motor
1. Variable Frequency Drive characteristics

HARSVERT-A series VFD is a masterpiece of outstanding performance and high reliability, which is widely used for the energy-saving application of the normal motors of fans, pumps, compressors, mills, conveyors and lifts. HARSVERT-A series VFD uses new type of IGBT with advanced microcomputer control.

High-High voltage resource VFD, direct 3, 3.3, 4.16, 6, 6.6, 10, 11 kV input, direct 3, 3.3, 4.16, 6, 6.6, 10, 11 kV output, no output up-transformer required.
Integrated dry type phase-shifting transformer design. The user only connects input/ output power cables and control cables. Each VFD is made inspection before leaving the factory.
Input power factor of more than 0.95 with the load of 20~100%, very low harmonic voltage/current, no power factor correction capacitor and harmonic filter required
Output sine step PWM waveform, no output filter required, VFD is directly connected to normal motor without the harm to the insulation of the motor and the cables. Soft start ability of VFD greatly reduces the impact to the power grid when the motor starts.
Output waveform of VFD does not bring the resonance of the motor. The torque impulse is less than 0.1%, which greatly reduce the resonance of the fan. VFD has frequency-skipping function to avoid the resonance of the system.
It is no limit to the length of the output cables. The motor is not influenced by very small common mode voltage and dv/dt.
Integrated microcomputer control and self-diagnosis ability. VFD displays detailed failure message in local interface and send the alarm to user's remote interface.
Local/ remote control; Communication protocols, such as Modbus, Profibus, TCP/ IP, DeviceNet, etc.
Torque characteristics: VFD can output constant rated torque from 0 to 50/60 Hz with torque step response < 200ms. VFD will output constant power with reduced torque for more than 50/60Hz.
VFD can ride through 35% voltage dip to continue operating without trip-off.
The mature technology of cascade-connected power cells keeps the good output waveform, which protect the motor and the cables well.
IGBT capacity is designed with high redundancy. Cell bypass[OPTIONAL FUNCTION] technology keeps VFD to continue operating when one or two power cells are in failure.
Auto re-start [OPTIONAL FUNCTION, FREE] after the recovery of power supply. When power supply is recovered in preset time, such as default time of 20s, VFD will fly start. VFD checks motor speed automatically and trace the speed to fly start again without impact.
Flying start[OPTIONAL FUNCTION].
Main circuit is connected to the controller by optical fiber, which make VFD extremely safe and away from electromagnetic disturbance.
Multi pulse rectifier technology, high power factor, few harmonics which directly comply with IEEE 519 harmonics standard.
Friendly interface based on WINDOWS CE system.
Optional redundant design for control power supply. VFD can accept two separate channels of auxiliary power supplies of single phase AC or DC for the controller from the user. The voltage is 110V, 220V, 230V, 380V, or 415V etc. If one channel of auxiliary power supply is in failure, the redundant channel of auxiliary power supply will immediately supply the power for the controller.
Automatically optimize the acceleration and the deceleration.
Perfect fault monitor and accurate protection. The basic protection includes over voltage, over current, low voltage, phase loss, over load, over heat, earth fault, and short circuit.
The failures of VFD include light failure and serious failure. VFD can continue to operate well with light failure.
Compatible with the standard analog signal of 0~10V or 4~20mA
Integrated PID regulator to make the flexible close control application
Cost effective VFD

2. Application
HARSVERT series medium-voltage VFDs are widely used in the following industry sectors.
Power generation: ID fan, FD fan, Primary air fan, Second Air fan, Condensate exhausting pump, Boiler feed water pump, Slurry pump.
Metal: Dust air fan, Primary air fan, Pump, Compressor.
Oil & Gas: Oil transferring pump, Water injecting pump, Electric submersible pump, Water Pump, Compressor.
Cement: Pre-heater fan, Coal mill fan, Cement mill fan, Bag house fan, Raw mill fan, Lignite Mill Filter Fan, By Pass Filter Fan, Kiln.
Mining: Conveyor, Lift, Pump.
Water: Pump.

Leader & Harvest is a main variable frequency drive manufacturer in China. 10 years experience taught us how to provide superior frequency converters. Now, our company has been guaranteed by ISO9001 and ISO14001 certificates. Our products have been exported to Europe, North America, South America, Africa, West Asia, Southeast Asia, Australia, among others. Meanwhile, as a variable speed drive manufacturer and supplier, we can also provide a full range of AC drivers, such as 3.3kV series VFD, 10kV series variable frequency drive, 11kV medium voltage frequency converter, etc., with high efficiency, reliable and safe use, energy saving and environmental protection. Due to these advantages, our VFDs are widely applied to electrical power, energy, mining, sewage treatment industries. We welcome customers all over the globe to contact us!

Feedback Form
Variable Frequency Drive
  • S VFD VFD will continue running in light failure;
    Smoothly soft start with the start current of less than the rated current of the motor;
    VFD can work well with the new exciter or the ...
  • VS VFD Vector control for the speed-adjustment of synchronous motor;
    Start ability for starting the synchronous motor with load;
    The response time of dynamic torque: less ...
  • FVS VFD PWM rectifier technology. Energy can flow bi-directionally between power grid and the motor;
    Vector control for synchronous motor;
    Strong start up with load in ...
  • FVA VFD Auto re-start after the recovery of main medium voltage;
    Fly-start at any rotating speed;
    Bypass the faulty power cell automatically( OPTIONAL FUNCTION) ...