VFD (Variable-frequency Drive) speed regulation and power saving effect and application

1. VFD (Variable-frequency Drive) speed regulation principle and application conditions Power transistors, inverters, large-scale integrated circuits and computer-controlled sine wave pulse width modulation systems are suitable for AC asynchronous motor speed regulation. The speed regulation principle is in line with the asynchronous motor speed formula N=60F(I—S)/P Relationship, where the speed N of the asynchronous motor is proportional to the frequency F of the power supply, changing the frequency F of the power supply can change the speed N of the asynchronous motor, and realize the AC speed regulation of the asynchronous motor. VFD (Variable-frequency Drive) is a device used to adjust the frequency of the power supply to adjust and control the speed of the AC motor. Next to the control room or electric cabinet, connect the power cord and the motor cord to the input terminals R, S, T and output terminals U, V, W of the VFD (Variable-frequency Drive) respectively (but the power supply cannot be connected to VFD (Variable-frequency Drive) output), put the setting parameters in the light touch button on the panel, and then realize the side-by-side adjustment and control of the AC asynchronous motor speed. Lead to the operation site (for example, install VFD (Variable-frequency Drive) in the fan room, lead the control power to the kiln surface for operation), use the button (or potentiometer) operator, and install the revolution meter (or frequency meter). Realize remote control, very convenient to use, easy to install and modify, no need to change the original equipment, only need to install a start control box on site or in the control room, so it is very suitable for poor working conditions and a large number of squirrel cages AC asynchronous motors are used for speed control and power-saving operation in factories and mines.

2 VFD (Variable-frequency Drive) specific application of speed regulation

2.1 Two sets of Nissan Fuji FRN160P7-4ES VFD (Variable-frequency Drive) are applied to the two kiln blowers to start, control and adjust the 380V-215kW double squirrel-cage AC asynchronous of two D60X90-250/3500 Roots blowers The speed of the motor is used to adjust the air volume of the blower into the kiln, and the speed regulation replaces the air release valve to release the air. The required power of the blower is significantly reduced, which has a significant power-saving effect. Kiln No. 1 saves 35% of electricity consumption, and No. 2 kiln saves 41.3% of electricity consumption. The soft start of the fan has been realized, which has overcome the damage to electrical appliances and machinery caused by the impact of high current when starting in the past, reduced maintenance, increased the operating rate, and improved the operation. Environmental conditions, noise reduction, application effect is very good.

2.2 Two unloading machines, the original 22kw electromagnetic speed regulating motor adjusts the unloading speed, which is easy to lock out of control, the intermediate bearing is easy to be damaged, the controller has many faults, and the operating rate is low, which affects production. Switch to Nissan Sanken 22K VFD (Variable-frequency Drive) to adjust the motor speed instead of electromagnetic speed regulation, the speed regulation performance is improved, the failure is reduced, the operation rate is improved, the maintenance cost is reduced, the operation power consumption is reduced, and the power consumption is saved by more than 40%. The application works well.

2.3 The ball forming machine with a diameter of 3.6 meters should use Nissan Sanken 22K VFD (Variable-frequency Drive) to adjust, adjust, and control the start and movement of the ball forming machine, increase the speed of the ball forming machine, improve the ball production and quality, and reduce the motor. Speed, reduce operating power consumption, saving up to 20%.

2.4 The two ball-forming and steady-flow screw machines were originally driven by two 11kW electromagnetic speed-regulating motors, and the load was unstable and often overloaded. They were replaced by Nissan Sanken 15K VFD (Variable-frequency Drive) speed control to control the screw speed Stable operation, reduce power consumption by 15%

2.5 Limestone chain conveyors are originally equipped with an electromagnetic speed-adjusting motor of 18.5 kilowatts to drive the B1000 chain conveyor to convey limestone. When the flow rate is large, the speed must be reduced. ), adjust the motor speed to adjust the speed of the original electromagnetic motor to the highest speed so that it can output normally and save electricity by 16%.

2.6 Limestone jaw crusher is applied Nissan Sanken 110K VFD (Variable-frequency Drive) speed control 75 kilowatts winding motor to drive 600*900 jaw crusher to crush limestone, keep the speed and working capacity of the jaw crusher without reducing, use The inertia of the flywheel reduces the speed of the motor and saves 20% of electricity consumption, so that the non-adjustable jaw crusher can also be used for energy-saving operation and achieve better economic benefits.

2.7 Limestone belt conveyor applies Nissan Sanken 110K VFD (Variable-frequency Drive) to adjust and control the operation of 5.5 kW motor, and stabilize the crushed stone flow at 30-40 Hz, so that the load and output of the hammer crusher are stable, and overload and no-load are prevented. Improve efficiency, reduce power consumption, and save electricity by 25%.

2.8 The clinker crusher is two 150*750 jaw crushers. The driving motor is large and the running time is long. Most of the time, light-load operation wastes electric energy. Nissan Sanken 22K VFD (Variable-frequency Drive) is used to adjust and reduce the motor speed. , maintain the speed and crushing capacity of the jaw crusher, and save 20% of electricity consumption.

2.9 Raw material batching speed-adjustable belt scales, using Taiwan Powtran 2.2K VFD (Variable-frequency Drive) speed-controlled batching belt scales to control 9 sets, to achieve stable batching and less faults, improve pass rate, increase operation rate, and reduce power consumption by 24% .

2.10 Nissan Sanken 30K and 15K VFD (Variable-frequency Drive) for production pumping and domestic pumping use speed control to control the operation of the pumps, and follow-up operation according to the water consumption to keep the pool full of water. Stable production overcomes the difficulty of pumping and stopping the pump The start-up can not pump water and affect production, which ensures that water does not flow everywhere, prevents waste, saves water by 20%, and saves electricity by 30%. 3VFD (Variable-frequency Drive) speed control application effect

3.1 VFD (Variable-frequency Drive) speed regulation is mainly to use its excellent speed regulation performance to improve the regulation quality of the process, especially in terms of improving the quality of ingredients, stabilizing the flow rate and discharging speed.

3.2 The application of VFD (Variable-frequency Drive) speed regulation technology solves the long-awaited AC speed regulation method, and finds a simple and effective speed regulation method for factories and mines that use a large number of squirrel-cage motors.

3.3 Frequency conversion speed regulation has excellent power-saving efficiency, because the reduction of the motor speed, the reduction of the shaft dynamic rate, the power consumption is the cube root times of the reduction of the speed, so it has a high power-saving ability. Before applying the frequency conversion speed regulation power saving technology, the company carried out a technical transformation and switched to low-loss transformers to adopt centralized compensation and local compensation power saving technology. The comprehensive power consumption per ton of cement was reduced from 92 kWh to 86.68 kWh. Secondary application of VFD (Variable-frequency Drive) speed regulation for power-saving technical transformation, the comprehensive power consumption per ton of cement dropped to 78.29 thousand