Multimeter use the matters needing attention

 Y2 series electric motor wholesale
Specifications
1. effiency: IE2 and IE1
2. 20 years manufacturing experience
3. 12 months guarantee
4. low noise and vibtration

(1) before using the multimeter,should be "mechanical zero",namely when no power being measured,the multimeter pointer refers to in the position of zero voltage or zero current.(2) in the process of using the multimeter,can't use hand to touch pens and metal parts,so that on the one hand can guarantee the accuracy of the measurement,on the other asynchronous motor hand also can guarantee personal safety.(3) in the measurement of a certain power,not in the measurement of shift at the motor vehicle same time,especially in measuring high voltage and large current,more attention should be paid to.Otherwise,can make the multimeter.For shifting,should first disconnect pens and,after the shift to measure again.(4) multimeter when use,must be placed,so as not to generator generator set cause the error.At the same time,but must pay attention to avoid the influence of external magnetic field on the multimeter.(5) the multimeter after use,should be the biggest block switch in the ac voltage.acmotortrading.blogspot.com If you don't use for a long time,also should be multimeter out internal battery,so as to avoid battery corrosion of other devices in the table.

Trapezoidal wave type in phase 5

AC induction cooling fan motor 
Specifications
1.Customised
2. good quality
3. 20 years manufacturing experience

 In the case of vector control, we main control corresponding to the rotor magnetic field parallel and perpendicular direction of motor current and voltage. This suggests that we measured by electrical current must pass a PI controller for mathematical calculations, and then from the stator three phase static structure into the lamination dynamic structure of rotor d - q (parallel and perpendicular to the rotor magnetic field direction). Also, the control voltage at the motor also need through mathematical calculation to its by the rotor structure of d - q into the stator three phase static structure, and then input to the PWM modulation part. These transformation requires that we have the ability of mathematical processing, DSP and high-performance processors will be used as the core of the vector control. Although the www.dongfeng-motor.com transformation of the structure to need one step calculation could be done, but we will use two steps to describe more convenient. 

Motor current first from the structure of the physics 120 degree phase stator three phase into a stable dynamic orthogonal orthogonal d - q structure, and then by the dynamic structure of the stator into the three-phase static structure of the rotor. In order to ensure effective results, these calculations must be P - I controller made within a sampling period. The above this kind of transformation and P - I needed for the controller voltage signal from the d - q structure into the phase structure of the stator coil operation just the opposite. Once the motor current is converted into d - q structure, control becomes very simple. We need two way P - I controller; A parallel control and rotor magnetic field of current, a vertical current control. Because of the parallel to the current control signal is zero, so it's make motor is parallel to 12v motor the current component is zero, it also have driven motor current vector all into vertical current. Since there is only vertical electric current to produce effective torque, motor efficiency is maximized. One P - I controller is mainly used to control the fan cover vertical current, torque demand in order to obtain consistent with the input signal. This also makes the vertical current was controlled in accordance with the requirements in order to obtain the required torque.

3 okw motor, 380 v voltage. The power factor is 0.2, could you tell me how to calculate the rated current?

electric motor 20hp aluminum body 
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1.AC motor aluminum body 
2.customized 
3. 20 years manufacturing experience 
4. competitive price,high quality 

Rated current I = P30KW U0.38 KV / 1.732 * * 0.2 = 227.9081 A, but electric motor 12v 500w 30 kw motor power factor can't be so low ah, do you want to calculate no-load running current of motor. The question you ask is problematic. ac three phase motor 30 kw motor power factor should be above 0.75. If according to the capacity of current rating: I = P30KW U0.38 KV / 1.732 * * 0.75 = 60.7755 A. Teach you two formula, very useful: "capacity divided by the number of kv, dealer by coefficient of seventh. "A kw, two current" can estimate the rated current of three-phase motor. Low power factor, then the acmotor2.blogspot.com motor should be banned the example of the net. Line current of three-phase ac asynchronous motor I material 2 P, P - power, kw. I material 2 x 60 kw motor current 30 = 60 a.

Bootstrapping IPM

Because general inverter circuit, the upper arm three IGBT trigger reference is suspended, so the upper arm trigger need 3 set of isolated power supply. The lower arm three IGBT trigger pulse is the common reference to, only a set of power supply. So a total of up to 4 groups of isolated generator set spare parts power supply. And mitsubishi DIP - IPM using bootstrap circuit structure, can easily achieve single power drive. Specific working principle is as follows: when the DIP - IPM start, first to lower arm IGBT ac motor send enough sufficient charging pulse number or a single pulse, opened lower arm (N) of IGBT, the power supply of the arm caused by internal charging path through IPM make upper arm three bootstrap capacitance charging completely, to the www.facebook.com/guohong.trading upper arm three IGBT trigger pulse power supply. Then began a PWM control pulse. Bootstrap charge circuit path and working 3 phase induction motor sequence diagram.

Direct torque control

 Direct Torque Control (Direct Torque Control, DTC), the text of the abroad some also called Direct self - Control, DSC, literal translation for Direct self Control, the concept of Direct self Control for Torque as the center for www.dongfeng- motor.com integrated Control, not only to Control the Torque, also used for the amount of flux linkage Control and flux linkage Control. The difference between the direct torque control and vector control is that it is not by controlling current, flux amount of indirect spare parts torque control, but the torque directly accused of quantity control, as the essence of which is using space vector analysis method, with the stator magnetic field orientation, the motor electric stator flux and electromagnetic torque in direct control. In 1985 Germany's ruhr university DiPu brock (m. epenbrock) professor is presented based on the first hexagon and round flux trajectory of the Direct torque control theory, he is called Direct self - control - DSC. This method does not need complex coordinate transformation, but directly on the motor fan cover stator coordinate computing the size of the torque and flux of the mold, and by direct tracking of flux and torque PWM pulse width modulation and high dynamic performance of the system.

3 okw motor, 380 v voltage. The power factor is 0.2, could you tell me how to calculate the rated current?

 Rated current I = P30KW U0.38 KV / 1.732 * * 0.2 = 227.9081 A, but electric motor 12v 500w 30 kw motor power factor can't be so low ah, do you want to calculate no-load running current of motor. The question you ask is problematic. ac three phase motor 30 kw motor power factor should be above 0.75. If according to the capacity of current rating: I = P30KW U0.38 KV / 1.732 * * 0.75 = 60.7755 A. Teach you two formula, very useful: "capacity divided by the number of kv, dealer by coefficient of seventh. "A kw, two current" can estimate the rated current of three-phase motor. Low power factor, then the acmotor2.blogspot.com motor should be banned the example of the net. Line current of three-phase ac asynchronous motor I material 2 P, P - power, kw. I material 2 x 60 kw motor current 30 = 60 a.

Three-phase asynchronous motor current sampling resistance

Sampling resistance and HCPL - 7840 connections, sampling resistor R1 is end connected to the Vin +, the negative terminals of fan cover the sampling resistor connected to the Vin? The real-time motor current is converted into analog voltage input chips; At the same time Vin? GND1 connection, and the return path of power supply and the sampling line connected to the negative terminals of the sampling resistance, because www.dongfeng-motor.com it is a lot of current when motor at work through the sampling circuit, parasitic inductance in the circuit can produce a large current spike, but this kind of connection can take these transient noise as a common mode signal, not for the sampling current signal interference; In addition, to eliminate the high frequency noise, sampling current input signal sampling resistor small diesel generator on the voltage signal have been collected by the R2 and C3 of low-pass filter into the chip.