Synchronous torque generated in step motor cannot make the rotor speed single phase motor price with the rotation speed of the stator magnetic field, causing loss of steps. Step out the main reason and solution: (1) the stepper motor torque, drag the ability is not enough, when the drive pulse frequency reaches a critical value began to step out. Due to dynamic output torque of stepping motor with the continuous rise in frequency and reduce, so any working frequency is higher than the frequency will produce out of step. There are three solutions: can make the electromagnetic torque of stepping motor to produce increased, therefore can within the scope of rated current and appropriate increase the drive current. Torque is insufficient in the high frequency range, appropriate to improve the driving voltage of the drive circuit, To switch to large torque of stepping motor, etc., also can make the stepping motor to overcome torque decreases, and therefore can be appropriately reduce the frequency of motor operation, in order to improve the output torque of the motor.
(2) step motor starting out of step. Because the stepping motor itself and the inertia load, when the accelerating time is too short will appear this phenomenon. Should set up reasonable acceleration time, make motor steady rise from low speed to a certain speed. (3) stepping motor to produce resonance is also a cause of out of step. The continuous operation of the stepping motor, if the control pulse frequency ac motor is equal to the natural frequency of the stepper motor, will produce resonance. In a control pulse cycle, vibration attenuation, has not yet been fully under a pulse has come, and so near the resonance frequency of dynamic error small diesel generator and leads to stepper motor out of step. The solution: reduce the stepper motor drive current. By adopting the method of subdivided driving and damping method. Rotor get too much energy in the process of step by step, the average speed of the rotor would be higher than the average rotational speed of the stator magnetic field, caused the stepper motor output torque increases, thus make the stepping motor produces more step. The step is when the stepper motor, the stepper motor can be reduced with the drive current, in order to reduce the output torque www.dongfeng-motor.com of stepping motor or make deceleration time longer.
(1) to determine the fuzzy controller input variables and output variables (2) design control rules of fuzzy controller (3) establish the blurred with the fuzzy method (4) select the fuzzy controller input variable and output variable in the theory field and determine the parameters of the fuzzy controller (quantitative factor and scaling factor) (5) the preparation of the application of fuzzy control algorithm (6) the rational selection of sampling time fuzzy control algorithm electric vehicle motor Generally use a two-dimensional fuzzy controller to the change of the error and error as input variables, to control the change of the quantity of output. The design of the fuzzy control rules generally includes: choose the word set of input/output variables, define a fuzzy variable fuzzy subsets and establish the control rules of fuzzy controller. The word set input and output variables, as a general rule, be {NB, NM, NS, NO, PO, PS, PM, PB}. Fuzzy variables of the fuzzy subset is to determine the shape of membership function of fuzzy ac electric motor subset. General use normal distribution. Control rules available conditional statements describe, that is, If A and B, Then C, Then control rules table is established.
Blur is the accurate quantity into fuzzy quantity, can use formula: Y = 12 X (a + b) / 2 / (b - a) accurate quantity is the actual range [a, b]. The output of the fuzzy control is a fuzzy quantity, it cannot directly control the controlled object, needs to be converted into precise volume. There are three methods: (1) selection of maximum membership degree method. The method is simple, less but the use of information; (2) take the median method; (3) the weighted average decision method, the use of information, but the large amount of calculation. Controller of the control algorithm can be written as if E = A (I) then EC = B (j) then U = C (ij) (I = 1, 2, 3,... m; j = 1, 2, 3,..., n) based on the sampling error, error change, can calculate the corresponding control quantity changes, to all the X, Y all the elements in the entire portfolio to calculate the corresponding control quantity change, U can be written as matrix (ij) (n * m) will be made table electricalmotor1.blogspot.com matrix, as A lookup table, to be stored in memory. After the real-time control, based on the fuzzy quantitative error value and error changes of look-up table directly, then set the scaling factor can be as the output to control the controlled object.
Capacitive
voltage transformer (CVT), in 1970 developed the domestic first 330 KVCVT, 1980 and 1985, developed the first generation and second generation KVCVT 500, electric motor 12v 500w 1990 and 1995, developed the third and fourth generation KVCVT 500, more than 30 years has accumulated rich experience in scientific research, development, design and production, in the domestic developed generation after generation of CVT new products, giving impetus to the development of www.dongfeng-motor.com the domestic CVT. CVT's main features are: High - electric strength, insulation margin is large, reliable operation. - can reliable damping ferroresonance. Successful adoption of the new group phase, with strict quality control, ensure that the factory's every fan motor piece of CVT are under any ac motor of the voltage from low to high effective damping various ferromagnetic resonance frequency. - good contact response characteristics. When the second time remaining after a short circuit voltage can fall below 5% in 20 ms, especially adapted to the fast relay protection. With power grid harmonic monitoring of patent technology.
This control strategy? For microcontrollers ST72141 adopted, the motor started by positioning to correct phase operation can arrange? Done, but must cooperate with the rotating inertia of the motor? And the load, the appropriate set some???? , just can make maximum ST72141 controller function. Figure 3.1 shows the motor start to seek after the registration, and then accelerate, the stable running and stop. Figure 3.2 as accept to start the motor life? After the motor starts to mandatory synchronization mode (forced synchronous mode), synchronization is this? In mode (synchronous switched mode) of the previous step, this process has been to the motor rotation speed is fast enough, namely? / event (Z - event), the point is over, to avoid the counter electromotive force is too weak?? Detection. Synchronization? In mode during the first work is motor of departure wholesalemotor.blogspot.com to the (startup), then the first counter electromotive force detection? Pay more to accelerate the motor gradually. If small diesel generator be in starting and accelerating (ramp - up) before the end of the haven't detected? Pay the point fan cover events, the motor will automatically stop. Then the motor into the synchronization? In mode (synchronous switched mode) and then into the automatic? In mode (auto - switched mode).
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.
And the stator magnetic field, the space of the stator current vector can be decomposed into vertical and parallel to the rotor magnet axis of two components. Vertical direction of the magnetic fields generated by the motor vehicle spare parts current component orthogonal to the rotor's magnetic field, this creates a rotating torque. And the magnetic axis parallel to the rotor current component, in line with the rotor magnetic field generated by the magnetic field, won't produce any moment. So, will need to make this a good control algorithm in parallel to fan motor the direction of the rotor magnetic axis and minimum current component, because the current component can make the motor only produce excess heat, and bearing wear. We need to control current of coil, in order to make magnetic axis perpendicular to the rotor current component in the direction of maximum.
Thus the motor torque and in proportion to the size of the current component. In order to effectively achieve sustained steady torque, we need an ideal steady magnetic field, to produce a stable stator current space vector, and the magnetic field need to follow the rotation of the rotor magnetic field with real-time vertical remain forever. From ac motor the perspective of the rotation of the rotor and the stator current space vector wholesalemotor.blogspot.com on the numerical value should be a stable value. So in the process of motor rotation, the space of the stator current vector representation should be a circle. As a result of the stator current vector is produced by the three groups of coil current component will overlap and become, and on the physical structure of the coil is the spacing between 120 degrees, so the motor current vector should be a string of three groups of ideal wave signal will overlap and become, at the same time, the three sets of strings is 120 degree phase Angle between wave signal.
Conduction mode and three three conduction mode The most common type of brushless motor, electric sequence diagram. Motor each turn a circle, there are six different state, each state has a 60 degrees. Also known as,. Conduction mode. Each state has two phase winding electricity, another set of closed. I am so understand, according to the position of the rotor rotation, different charging state of the switch. As long as according to certain order cycle power up, the rotation of the motor can be kept. To adjust the winding voltage (PWM), which can realize speed regulation. Here in the way of sensorless rotor position detection method. Counter electromotive force (EMF) detection method. Brushless electric motor fan cover dc motor of the counter electromotive force (EMF). The dotted line in the graph, said of the phase counter electromotive force (EMF) of the waveform.
Counter electromotive force (EMF) and 1/2 motor voltage intersection point, known as ZERO point (ZERO). Can be seen in the figure, the ZERO (ZERO) than the phase Angle is 30 degrees ahead of time. As long as the detection to the ZERO point (ZERO), and then delay 30 degrees, you can know the position of the rotor. As long as ac motor the loop detector ZERO (ZERO), accurate phase, which can realize the rotation of the motor. Due to the first contact to touch, first not further discuss the time delay of 30 small diesel generator degrees, also can say 30 degrees ahead of commutation. The reason is the web site has been successfully by the case. Say again below ZERO (ZERO) detection method. Using the function of three resistance is no matter in which state, motor is negative plate can ensure the comparator input for 1/2 of the motor voltage. The positive input of the comparator, through a multi-channel electronic switch, in different state, switch to a different www.dongfeng-motor.com port. Each state can be detected is zero.
Able to provide a stable voltage and frequency of power supply according to ac regulated power supply.At present most domestic manufacturers is the work done by ac voltage stability.Below the market some ac regulated power supply,the classification characteristics. motor vehicle spare parts Parameter adjustment (resonance):this kind of regulated power supply,voltage stability is the basic principle of LC series resonance,the early type of magnetic saturation voltage stabilizer is belong to this category.It has the advantage of simple structure,without many of the components,reliability is quite high ac electric motor voltage range is wide,strong anti-jamming and resistance to overload ability.The disadvantage is that large energy consumption,noise big,bulky and high cost.On the basis of the principle of magnetic saturation of development into the formation parameters voltage stabilizer and China have been popular in the 50 s of "magnetic amplifier gather digital ac voltage stabilizer" (614) are the principle of ac voltage stabilizer.Autoformer (than) gather: 1,mechanical pressure regulating type,i.e.,according to the servo motor to drive the carbon brushes in autotransformer winding sliding surface move,change Vo on the ratio of the Vi,in order to realize the adjustment of the output voltage and stability.
The voltage stabilizer can from several hundred to several kilowatts.It is characterized by simple structure,low cost,the output waveform distortion small; But because the carbon brush sliding contact are prone to edm,brush damage that burned and failure; Slow speed and voltage regulation.Type 2,change the tap,autotransformer to make multiple fixed tap,through a relay or SCR (SSR) as switch machine 10,automatically change the tap position,so as to realize the stability of output voltage.This type of circuit voltage regulator the method is simple,wide voltage stabilizing range (130 v to 280 v),high efficiency (95%) or higher,the price is low.While the disadvantage is that low voltage stabilizing precision (plus or minus 8 ~ 10%) working life is short,it is suitable for the family to the air conditioner power supply.Power voltage compensation type electrical motor - purifying type (including precise voltage stabilizer) it USES compensation link to realize the output voltage stability,easy to implement microcomputer control.It has the advantage of good anti-jamming performance,high precision voltage (+ / - 1%) or less,fast response (40 ~ 60 ms),simple circuit,reliable operation.
The disadvantage is that: with the computer,program-controlled switches,such as nonlinear load are low frequency oscillation phenomenon; Input side current distortion degree is big,the source power factor is low; The output voltage to input voltage phase shift.Against interference function to demand higher units,it is advisable to apply in the city,computer power supply,must choose the computer about 2 to 3 times the total power voltage regulator to use.Because has stabilized,anti-jamming,the advantages of fast response speed,moderate price,so widely used.Switching regulated power supply: it is applied to the high frequency pulse width modulation technology,and it is the difference between general switch power supply output must be with the input side of the same frequency and phase ac voltage.It had quasi square wave output voltage wave type,type of ladder wave,sine wave,etc.,in the market for uninterruptible power supply (UPS) from the storage power supplies and chargers,ac voltage regulator is a switch mode power supply voltage regulator and control function is strong,easy to realize intelligent,is a very promising ac regulated power supply.But because of its circuit www.facebook.com/dongfeng.motor is complex,the price is higher,so to promote more slowly.
Brushless motor driven trapezoidal wave control mode of the frame. motor parts Here a PI control circuit is used to to control current. We use the actual measurement of the current demand and current comparison, get a deviation signal. This deviation signal through the integral and magnified and produce an output correction value, the deviation value is used to reduce the error. This spare parts produced by P - I control loop correction value through PWM setting, then to provide output bridge road. The purpose of this procedure is to ensure that any of the current in the coil remained stable state. Change of phase current control part without any contact. Motor hall sensor in fan motor the wholesalemotor.blogspot.com position signal is used to choose which a pair of coil way need to pass to current corresponding to the output of the bridge, while the other bridge road keep current status. Current sensing circuit is mainly used to real-time current of electric coil, and the feedback signals to the current control loop.
IRMCF341 international rectifier (IR) in the United States new sensorless control for variable frequency electrical appliances application of high performance low cost motor control IC. It adopts the most advanced based on the motor vehicle spare parts magnetic field orientation vector control technology, using the single resistance current sampling the motor can be realized in three phase current refactoring, so as to realize the FOC current loop and speed AC synchronous generator loop, double closed-loop vector control, drive mode for 180 degrees of sine wave. IRMCF341 contains two high-performance processing engine, one is 8 bits high- speed 8051 cores, generator set spare parts the other one is to control the motor sensorless control of 16 engines (MCE). 8051 nuclear execution speed for every two system clock an instruction (such as: 60 MIPS @ 120 MHZ system clock). 8051 nuclear and MCE processor: by dual port RAM data exchange between so as to realize the function of data monitoring and command input.
MCE contains all the necessary based on hardware circuit control motor control resources, such as PI regulator, vector rotation, Angle estimator, multiplication/divider, low loss of SVPWM, and single resistance current sampling/restructuring, and so on. Sensorless control algorithm of the key elements of complex (such as: Angle estimator) all have defined acmotortrading.blogspot.com control module, the user can through the use of the seamless connection with MATLAB/SIMULINK environment graphical compiler to design your own motor control algorithm (in MATLAB/SIMULINK environment by connecting the modules function module and compiles). 8051 code simulation and debugging can be through a third party based on JTAG mouth debugging tools to complete. Procedure in 51 IRMCF341 memory to 48 k RAM, packaging form for small QFP64 lead-free packaging.
Situation:in the double liang steam double-effect lithium bromide absorption air-conditioning unit,the use of omron PLC (PA204S C200HE-CPU42,power supply) to control the start of two pumps. When,in turn,start the two pumps,often led to the suspension of the power of the PLC,thus stop running program.Second,the detection of 1,use the meter to measure the voltage electric motor 12v 500w waveform of two pump ordinal startup PLC power PA204S ac voltage of the power supply change found:when did not start the electrical motor 12v 1000w pump,the voltage of the power supply is normal,when start the two pumps,instantaneous fell to the power supply voltage of 184 v,184 v and the duration of the above 25 ms,PLC to stop working,and to determine the effect of pump power of PLC.2,in order to solve this problem,respectively for the following tests: A) driving the pump first,delay around 10 s to start small pump,power supply voltage drop to about 190 v,the instructions first,pump makes instantaneous voltage drops,later start small pump,affect smaller,but it need to modify the PLC program.
B) because the pump power supply is turned by high tension line through a transformer,transformer capacity,can be considered a large capacity of transformer,may make the pump will be smaller influence on the PLC power supply voltage.C) in the PLC power supply termination a large capacitance,but the effect is not obvious.D) finally in one power supply transformer converted by a 220 v power supply to PLC,found that even in the start two pumps at the same time,PLC power supply voltage drop is only about 204 v,204 v,the can.Conclusion:as a result acmotortrading.blogspot.com of the PLC power supply is supplied with water pump in the same way,and the plant's transformer capacity is small,so in the start two pumps,caused the PLC power supply voltage drops below 85% of rated voltage,and duration of more than 10 ms,resulting in PLC detected power interruption,stop working. So the advice from the transformer converted one by one in the 220 v power to separate for PLC,which can solve the problem.
Control of brushless dc
motor is one of the most simple way is the so-called "trapezoidal wave type" commutation. In this scheme, we only control a pair of the current in the motor coil, and the third line generator set spare parts circle has been in contact with the power supply is not in the circuit. Installed in the motor internal hole signal once every 60 degree Angle detection, and the detected results through digital signal feedback to the controller electric vehicle motor part of the motor. Because in the case of trapezoidal wave commutation, only two sets of coil motor is connected with the same current, and the third group of coil current Induction motor is zero, so this way of testing the motor rotation can only be detected in a lap six direction of current vector. In the process of motor rotation, the motor current once every 60 degree change, so each current vector only within the scope of wholesalemotor.blogspot.com current calibration about 30 degrees. The current waveform from zero step jump to a positive maximum current, and then to zero, then into a negative maximum current. In this case, the motor current in the six regional jump regularly, make motor can approximate running smoothly.
FOC control algorithm refers to:the motor in the three-phase system of stator ac current Ia,Ib,Ic,by three phase - two phase transformation (CLARK transformation),equivalent to two phase static www.facebook.com/guohong.trading coordinates system,ac current Ia1Ib1 again by pressing the rotor field-oriented rotation transform (PARK transformation),equivalent to dc current Im1,It1 under synchronous rotating coordinate system (Im1 is equivalent to motor parts the excitation current of dc motor; It1 and torque is proportional to the armature current),and then imitate the dc motor control method,control of dc motor is obtained. Then use the PARK transformation,the CLARK transformation transform dc control volume for the required three intersection traffic,and then control the motor. Since fan motor 341 with no transfer of control method,and the beginning of the beginning of 341 does not start in a closed-loop manner,its startup mode is as follows:first,by applying specific to the motor vector,forcing the rotor moves to the specified lamination location (PARK). To PARK at the end of the open loop operation of electric Angle as the starting point,and reach the threshold speed closed-loop model,after if magnetic flux test is successful,achieve real closed-loop control,implement FOC control algorithm.
Two 0.75 KW..Grade 4...380 v...The motor..No-load current is between 2.3 to 2.6...Work environment textile factory..'a lot...Rated current of the motor is only 2.2...Normal no-load current is around 1.6..Time machine completely under ac electric motor the condition of no load over current...Due to the current big.So high temperature sharply born..Will soon..Overheating damage..Do not say the reason...thank you Problem complement: I thank two answer first..Disease,and together,the two are not normal before..In a few years later.You'll find the bad one current is increased.[.Repair of the motor are friends.Eliminate offline ribbon..] ...Until now,with or without load..Motor current wholesalemotor.blogspot.com is bigger...Last year when the motor current in 2.0 A..Now 2.4-2.5 A...Motor shaft sleeve inside and outside in good condition.
Have not completed...Don't go...Only electricity pilot time to run the old hot..Often the temperature in the 60-80 degrees...Wiring is right...Are the normal installation... There is a reason,is you pick the wrong wiring.380 v y connection.You make into 380 v delta connection.So,motor heat quickly.This is one magnetic generator of them.In addition,the machine is idle for a long time,must have certain load.If it is in use for a period of time after the scenario (excluding intervention had gone wrong),should be the result of mechanical failure.1 bearing damage increase torque resistance.Run 2 bearing outer ring,which leads to the bearing wear gaps (cover),the rotor eccentricity running and friction with the stator (boring),increase the electric motor 12v 500w torque resistance.What type of your motor,then measure the core size,what are you friends with line,around a few laps? I help you check it.Is estimated to be between winding insulation damage,it is recommended that you access the winding.
Seg also USES frequency conversion air conditioning haier 98 c029 special large scale integrated circuit, the small diesel generator chip temperature collection, over- current, overheating, prevent the protection function such as frozen, can also be 30 ~ 125 hz PWM output pulse signal, drive the compressor, the air conditioner from one to three horses. Emergency turns, fixed fan cover output of 60 hz frequency operation, then can carry out measuring pressure, current and so on maintenance work. Transmitted from the cPu receives outdoor indoor machine (cooling, heating, wet, compressor operation frequency) control signal, such as outdoor fan control, four-way valve, and through the inverter control imposed on the compressor motor ac motor frequency and voltage, and transform the running speed of the compressor. At the same time also will feedback the information about the operation of outdoor www.facebook.com/guohong.trading to indoor machine.
Of the
output voltage is on-board host on-board power amplifier output audio signal voltage,usually under 10 v.On-board host in the car audio system similar to the original function of DVD home theater,but inside the car space is precious,so integration is very demanding.In order to satisfy ac induction motor the space requirements,many car the host with the function of the power amplifier,can be connected directly to the ac electric motor speaker.But a host of power amplifier sometimes can't satisfy people's needs,so a lot of host electricalmotor1.blogspot.com (but not all of the host) can connect independent power amplifier.Unlike home theater VCD,a prerequisite for the host output voltage is higher,so the different host to the requirement of diesel generators prices the power amplifier,when the choose and buy should pay attention to collocation.If you choose the car amplifiers,had better choose lead high output current host,currently in power output is preferred.
Two 0.75 KW..Grade 4...380 v...The motor..No-load current is between 2.3 to 2.6...Work environment textile factory..'a lot...Rated current of the motor is only 2.2...Normal no-load current is around 1.6..Time machine completely under ac electric motor the condition of no load over current...Due to the current big.So high temperature sharply born..Will soon..Overheating damage..Do not say the reason...thank you Problem complement: I thank two answer first..Disease,and together,the two are not normal before..In a few years later.You'll find the bad one current is increased.[.Repair of the motor are friends.Eliminate offline ribbon..] ...Until now,with or without load..
Motor current wholesalemotor.blogspot.com is bigger...Last year when the motor current in 2.0 A..Now 2.4-2.5 A...Motor shaft sleeve inside and outside in good condition...Have not completed...Don't go...Only electricity pilot time to run the old hot..Often the temperature in the 60-80 degrees...Wiring is right...Are the normal installation... There is a reason,is you pick the wrong wiring.380 v y connection.You make into 380 v delta connection.So,motor heat quickly.This is one magnetic generator of them.In addition,the machine is idle for a long time,must have certain load.If it is in use for a period of time after the scenario (excluding intervention had gone wrong),should be the result of mechanical failure.1 bearing damage increase torque resistance.Run 2 bearing outer ring,which leads to the bearing wear gaps (cover),the rotor eccentricity running and friction with the stator (boring),increase the electric motor 12v 500w torque resistance.What type of your motor,then measure the core size,what are you friends with line,around a few laps? I help you check it.Is estimated to be between winding insulation damage,it is recommended that you access the winding.
To our factory after the high temperature in the summer of 220 kv current transformer oil 8500w gasoline generator leakage happened again and again,in my factory using the 220 kv current transformer,Ⅰ Ⅲ period switching station unimproved interval chosen are the products of the nanjing,cichang,four switching station and Ⅰ - Ⅲ switching station is interval with both hunan liling cichang the production of products.Product www.facebook.com/guohong.trading model are LB9-220,the whole sealing oil-immersed capacitive current transformer.Found in the run up to the defects of oil leakage phenomenon caused by untight seal,oil for a small amount of outdoor oil-filled electrical equipment are more 12v motor likely to cause equipment insulation parts be affected with damp be affected with damp,untight seal main insulation damage,causing more severe accidents,such as dielectric loss,the single phase electric motor excess oil chromatogram or explosion.Therefore,for small oil amount of outdoor oil-filled electrical equipment oil leakage defects timely processing,should be given enough attention in the work.
(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 generator generator set 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 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.
Situation:in the double liang steam double-effect lithium bromide absorption air-conditioning unit,the use of omron PLC (PA204S C200HE-CPU42,power supply) to control the start of two pumps. When,in turn,start the two pumps,often led to the suspension of the power of the PLC,thus stop running program.Second,the detection of 1,use the meter to measure the voltage electric motor 12v 500w waveform of two pump ordinal startup PLC power PA204S ac voltage of the power supply change found:when did not start the electrical motor 12v 1000w pump,the voltage of the power supply is normal,when start the two pumps,instantaneous fell to the power supply voltage of 184 v,184 v and the duration of the above 25 ms,PLC to stop working,and to determine the effect of pump power of PLC.2,in order to solve this problem,respectively for the following tests: A) driving the pump first,delay around 10 s to start small pump,power supply voltage drop to about 190 v,the instructions first,pump makes instantaneous voltage drops,later start small pump,affect smaller,but it need to modify the PLC program.
B) because the pump power supply is turned by high tension line through a transformer,transformer capacity,can be considered a large capacity of transformer,may make the pump will be smaller influence on the PLC power supply voltage.C) in the PLC power supply termination a large capacitance,but the effect is not obvious.D) finally in one power supply transformer converted by a 220 v power supply to PLC,found that even in the start two pumps at the same time,PLC power supply voltage drop is only about 204 v,204 v,the can.Conclusion:as a result acmotortrading.blogspot.com of the PLC power supply is supplied with water pump in the same way,and the plant's transformer capacity is small,so in the start two pumps,caused the PLC power supply voltage drops below 85% of rated voltage,and duration of more than 10 ms,resulting in PLC detected power interruption,stop working. So the advice from the transformer converted one by one in the 220 v power to separate for PLC,which can solve the problem.
The
motor is driven by a small centrifugal pump,bearing also just changed,center also from the new correction,disintegration of pump is no defect,but there is always the phenomenon of fever and excessive current and motor magnet motor noise? Please some directions No-load current of the motor is 20-50% of rated current commonly,if too much no-load current should undertake the following check. 1 phase voltage of the motor parts stator winding is high 2 whether take star wiring fault into Angle 3 motor air gap is too big 4 internal wiring for error 5 stator windings wire diameter is too small,6 7 of electricalmotor1.blogspot.com the rotor iron core is neat assembly quality is unqualified,whether bearing lubrication good 8 core weight too small nine winding inside do you have any short circuit,open circuit or ground fault for you is wrong,but I'd give you the answer,the 7.5 KW motor is impossible to 15 ma of current,should be 15 Ann,you electrical motor 24v put the motor no-load test run first to measure current if current is disposed of in accordance with the method of the above,if the current normal pump you have any question.
Electrical failure of the stator windings without phase operation,the reverse of the stator winding unbalanced three phase current,winding short circuit and grounding,heating winding and rotor broken bar,open circuit,etc.Lack of phase operation is one of the common faults.As long as there is a phase in the asynchronous motor three-phase power supply circuit can cause motor open phase running.Lack of phase operation may be due to line fuse melt fuse,switch contact or wire connector causes such as poor contact.When the power is short of a three-phase motor phase,such as in stop state,due to the synthesis of zero torque and blocked,the inability to start).The locked-rotor currents of the motor current is much larger than normal work.Apply generator generator set power,therefore,in this case the time is too long or more frequent start turning on the power supply will lead to motor burn down.
Running motor is short of a phase,such as load torque is small,still can maintain operation,only speed decreases slightly,and abnormal noise; When the loads,the operation time is too long,will make the motor winding burn.Three-phase winding fore and electricalmotor1.blogspot.com aft misconnect when,after turning on the power supply will be three phase current serious imbalance,reduced jumps,vibration,temperature rise of the rotating speed,the phenomenon such as voice radically.If not protection device,it is easy to burn out motor winding,so must see first,tail motor wire end,before electricity operation.Three phase current unbalance fault,often caused by motor external power supply voltage imbalance,the motor parts internal reason mainly is the winding interturn short circuit or in motor rewind coil number of turns or wiring errors when repaired.Winding grounding and short circuit current is too large.Ground fault available megohmmeter.Can reduce in the stator winding voltage short-circuit fault case,judged by measuring the current,can also measure the dc resistance to judgment.
