How does inverter save energy?1. Control the starting current of the motorWhen the motor is directly started through the power frequency, it will produce 7 ~ 8times of the rated current of the motor, which will greatly increase the electricalstress of the motor winding and generate heat, thus reducing the life of the motor. Thefrequency converter speed regulation can be used under the condition of zero speed andzero voltage. Once the relationship between frequency and voltage is established, thefrequency converter can drive the load to work according to V / f or vector control. Theuse of frequency converter speed regulation can fully reduce the starting current andimprove the bearing capacity of the winding. The direct benefit to the heatingenterprises is that the maintenance cost of the motor is further reduced and the servicelife of the motor is increased.2. Reduce the voltage fluctuation of power lines and improve the quality of power gridWhen the motor starts at power frequency, the current will increase sharply, and thevoltage will fluctuate greatly. The range of voltage drop will depend on the power ofstarting motor and the capacity of distribution network. Voltage drop will lead to faulttrip or abnormal operation of voltage sensitive equipment in the same power supplynetwork, such as DCS system, PC and contactor. After adopting frequency conversion speedregulation, starting gradually at zero frequency and zero voltage, the voltage drop canbe eliminated to the greatest extent.3. Lower power is required when startingThe motor power is proportional to the product of current and voltage. The powerconsumed by the motor directly started by the working device will be much higher thanthe power required by the inverter. The direct start of 315KW circulating pump will havea serious impact on other equipment, even make the transformer over-current trip, so asto be warned by the power sector. The inverter is used for power supply If the engineis started or stopped, similar problems will not occur.4. Adjustable acceleration and deceleration functionSpeed and torque limit inverter speed control can be set according to the needs of usersfreely acceleration and deceleration time, its acceleration and deceleration mode canalso be selected, such as, linear, S-type, etc. In this way, the motor or the connectedmechanical part of the shaft or gear will not produce severe vibration, further reducingthe mechanical wear and loss. At the same time, it can easily and smoothly adjust therunning speed by adding potentiometer or manual operator. After speed regulation byfrequency converter, it can set the corresponding torque limit to protect the machineryfrom damage, so as to ensure the continuity of the production process and thereliability of the product. The current frequency conversion technology makes the torquelimit adjustable, and even the torque control accuracy can reach about 3% ~ 5%.5. Variable frequency speed regulation is used for pump water pipelineIn the heating enterprises, the utilization rate of water pump is the highest, and thewater hammer effect is the most prominent and the most important problem to be solved.When the electric water pump starts under the full pressure, the starting time is lessthan 1 second. In less than 1 second, the flow of the pipeline increases from zero torated flow. The very sharp change of fluid flow will produce the impact force of toohigh or too low pressure in the pipeline, and the phenomenon of / cavitation 0 effectmay appear.The pressure impact on the pipe wall will produce noise, just like the hammer hittingthe pipe, which is called / water hammer effect 0. Water hammer effect not only producesnoise, but also causes physical damage. At the moment when the pressure is too high,the pipe may break. When the pressure is too low, the tube will collapse. The cavitationeffect will cause the strong agitation of the liquid, which will lead to the erosion ofthe inner wall of the pipe and the vaporization of the liquid. In addition, the waterhammer effect may also damage the valves and fasteners. In case of direct shutdown, thepotential energy of the liquid will overcome the inertia of the motor and make thesystem stop sharply, which will also cause pressure impact and water hammer effect.After adopting frequency conversion speed regulation, the rise and fall time can be setaccording to the needs, so that the flow rate change rate in the pipeline system can bereduced to the allowable range, so as to completely eliminate the water hammer effect.Not only the method is very simple, but also the effect is the most ideal.
