Energy saving principle of frequency conversion motor

|2015-06-01 09:05|7944 view

Energy saving principle

1、变频节能

1, frequency conversion energy saving

由流体力学可知，P（功率）=Q（流量）╳ H（压力），流量Q与转速N的一次方成正比，压力H与转速N的平方成正比，功率P与转速N的立方成正比，如果水泵的效率一定，当要求调节流量下降时，转速N可成比例的下降，而此时轴输出功率P成立方关系下降。即水泵电机的耗电功率与转速近似成立方比的关系。例如：一台水泵电机功率为55KW，当转速下降到原转速的4/5时，其耗电量为28.16KW，省电48.8%，当转速下降到原转速的1/2时，其耗电量为6.875KW，省电87.5%.

As indicated by the fluid mechanics, P (power) =Q (flow) (H (pressure) and a flow rate Q and the rotational speed n is proportional to the. H pressure and rotational speed n is proportional to the square, the power (P) and speed (n is proportional to the cube, if the decline in the efficiency of the pump, when the requirements of the regulation of flow down, turn speed n can be proportional to, but this time shaft output power P into cubic decrease. The pump motor power consumption and speed than the establishment of the approximate relationship. For example: a pump motor power is 55kW, when the speed is reduced to 4 / 5 of the original speed, its power consumption is 28.16KW, power-saving 48.8%. When the speed is reduced to 1 / 2 of the original speed, its power consumption is 6.875KW. Power was 87.5%.

2、功率因数补偿节能

2, power factor compensation energy saving

无功功率不但增加线损和设备的发热，更主要的是功率因数的降低导致电网有功功率的降低，大量的无功电能消耗在线路当中，设备使用效率低下，浪费严重，由公式P=S╳COSФ，Q=S╳SINФ，其中S－视在功率，P－有功功率，Q－无功功率，COSФ－功率因数，可知COSФ越大，有功功率P越大，普通水泵电机的功率因数在0.6-0.7之间，使用变频调速装置后，由于变频器内部滤波电容的作用，COSФ≈1，从而减少了无功损耗，增加了电网的有功功率。

The COS, cos consumption leads to a decrease in not only increase the reactive power loss and equipment of fever, more important is the power factor of power grid power is reduced, a large number of reactive power in the line and equipment use efficiency is low, a waste of serious, by the formula of P-S (phi Q=S (sin Phi which s apparent power, P - active power, q - reactive power, cos Phi - power factor, it can be seen that the diameter of the active power P, common pump motor power factor at 0.6-0.7, the use of variable frequency speed regulating device, due to the frequency converter internal filter capacitor, cos Phi = 1, so as to reduce the reactive power loss and increase the power active power.

3、软启动节能

3, soft start energy saving

由于电机为直接启动或Y/D启动，启动电流等于(4-7)倍额定电流，这样会对机电设备和供电电网造成严重的冲击，而且还会对电网容量要求过高，启动时产生的大电流和震动时对挡板和阀门的损害极大，对设备、管路的使用寿命极为不利。而使用变频节能装置后，利用变频器的软启动功能将使启动电流从零开始，最大值也不超过额定电流，减轻了对电网的冲击和对供电容量的要求，延长了设备和阀门的使用寿命。节省了设备的维护费用。

Due to the motor for direct start or Y / d start, the starting current is equal to (4-7) times the rated current, it will cause serious impact on Electrical and mechanical equipment and power grids, but also asking too much capacity on the grid, the high current and the vibration generated when starting on baffle and valve damage damage greatly, the service life of equipment, piping is extremely unfavorable. After the use of the frequency conversion energy-saving device, the use of frequency converter soft start function will make the starting current starting from scratch, will not exceed the maximum rated current, reducing the impact on the power grid and the power supply capacity, and prolongs the service life of the equipment and valves. Save the maintenance cost of the equipment.

变频器可以省电这是不可磨灭的事实，在某些情况下可以节电40%以上，但是某些情况还会比不接变频器浪费！

Inverter can save energy which is an indelible fact that in some cases can save 40% or more, but some of the situation will be more than inverter waste!

变频器是通过轻负载降压实现节能的，拖动转距负载由于转速没有多大变化，即便是降低电压，也不会很多，所以节能很微弱，但是用在风机环境就不同了，当需要较小的风量时刻，电机会降低速度，我们知道风机的耗能跟转速的1.7次方成正比，所以电机的转距会急剧下降，节能效果明显。如果我们用在油井上，就会因为在返程使用制动电阻白白浪费很多电能反而更废电。

Inverter is through the light load step-down to achieve energy-saving, drag torque load because there is no change in the speed, even lower voltage, not a lot, so energy is very weak, but in fan environment is different, when need smaller air time, the motor will reduce the speed, we know that fan energy consumption and speed of 1.7 times is proportional to the square, and so the motor torque will be a sharp decline, energy saving effect obviously. If we use in the well, will be because of the use of a braking resistor in vain to return power but also waste a lot of waste electricity.

当然，如果环境要求必须调速，变频器节能效果还是比较明显的。不调速的场合变频器不会省电，只能改善功率因数。

Of course, if the environment requires speed adjustment, inverter energy saving effect is obvious or obvious. The frequency converter with no speed will not save energy, but can improve the power factor..

1、如果两个一模一样的电机都工作在50HZ的工频状态下，一个使用变频器，一个没有，同时转速和扭矩都在电机的额定状态下，那么变频器还能省电吗？能省多少呢？

1, if two identical motors work under 50Hz power frequency, a frequency converter, a not, at the same time speed and torque are in the motor under rated condition, then the inverter can also save electricity?? How much can province?

答：对于这种情况，变频器只能改善功率因数，并不能节省电力。

A: for this situation, the inverter can only improve the power factor, and can not save electricity.

2、如果这两个电机的扭矩没有达到电机的额定扭矩状态下工作（频率，转速还是一样50HZ），有变频器的那个能省多少电？

2, if the two motor torque did not reach the rated torque state of the motor (frequency, speed is still as 50HZ), how much power inverter that can save?

答：如果使用了自动节能运行，这个时刻变频器能降压运行，可以节省部分电能，但是节电不明显。

Answer: if the use of automatic energy saving operation, this time converter can buck operation, can save part of power, but power is not obvious.

3、同样的条件，空载状态下能省多少，这三种状态下哪个省的更多？

3, the same condition, no-load state can save how much, which three state which province more?

优点

Advantage

1、具备有启动功能。

1, have the starting function.

2、采用电磁设计，减少了定子和转子的阻值。

2, the electromagnetic design, reduce the stator and rotor resistance.

3、适应不同工况条件下的频繁变速。

3, adapt to the frequent variable speed under different working conditions.