Fly-wheel diode method is also called the "third phase conduction method", it is through the parallel inverter bridge on the power switch tube fly-wheel diode conduction and shut off state testing to determine the rotor position. This method applies to 120 ° conduction, three-phase six-step square wave permanent magnet brushless dc motor drive, the implementation scheme of main circuit and power required by the device PWM timing, respectively, as shown in figure 3 (a), (b). Below to T in the chopper, a T b - in the stage of conduction as an example to illustrate its working principle. When T a + from opening to shut off, if the winding self inductance, mutual generator set spare parts inductance are constant, the terminal voltage phase C can be expressed When ec = 0, ea + 4 = 0, V CE, V F is very small, can be ignored.
so the stream diode conduction approximation for the conditions of ec < 0, as long as the detection of D C - conducting state, can detect the C instead of electric potential zero; Appropriate delay, conduction T C - again, and again, can correctly commutation sequence, in turn trigger different power tube, drive motor rotation. wholesalemotor.blogspot.com Fly-wheel diode method the ac motor essence or the potential laws, only in the "disconnect" back emf zero detection have some change. This change in a certain extent, to broaden the motor lamination speed range, especially can widen the lower limit of motor speed, because the fly-wheel diode conduction voltage drop is small, as long as the sensorless brushless dc motor control - liuyunqian @ yeah - embedded learning can, CE and V F and V are usually small. In some applications, the minimum speed of the motor can even less than 100 r/min.
(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.
Three-phase straight? Brushless motor basic drive method, divided into rectangular wave drive and are XuanBo drive. The former will 6 switch with simple ON/OFF - signal drive motor runs, the driving mode of the latter as the general due? The motor, the stator end input three-phase sine wave signal, synthesis of a rotating magnetic field to drive the rotor rotation, the workings of the motor as permanent magnet due? Synchronous motor, because of this? Using the rectangular wave drive motor runs, so the sine wave driving mode? In the single phase motor description. Rectangular wave driven approach is divided into 2 kinds, 120 ° square wave drive with 180 ° square wave drive, as shown in figure 2.4.
By conducting 6 switch control current? , can be in 6 of the direction of the magnetic field is generated in the motor as shown in figure 2.5, attract the rotor reach 6 point, through the change of the switching sequence, can make the motor rotation. In the actual application, because 180 ° square wave drive every time conduction switch from 120 ° square wave wholesalemotor.blogspot.com drive one more, its work? The loss is bigger. And configuration on the motor of the hall element (its USES in the next section? Ming), usually applies to 120 ° square wave drive, so? Is to use 180 ° square wave drive, the hall element output signals must be fan cover offset Angle of 30 ° electrical appliances, office? More trouble, so in the actual use mostly driven by 120 ° rectangular wave. In this? Article 120 ° motor drive mode was adopted in the rectangular wave driven.
State observer method, calculation method of rotor position is will be coordinate transformation motor three-phase voltage, current, on the basis of the park equation one way to estimate the motor rotor position [2]. This method in recent electric motor 12v 500w years abroad far more [9]. The basic principle of this method to detect the rotor position signal is: the motor under a2b2c coordinate system of three-phase measured phase current and phase voltage conversion to represent the A2B hypothetical rotor position coordinates (the Angle of the two coordinate difference is $H); According to the coordinates of the current by parker equation to calculate the three-phase voltage value; Comparing the voltage and the front by converting the voltage difference, can have the function relationship between $U = f ($H).
The derivation can be found: when $H - > 0 $U ∝ $H, so can use a state observer to look at $U, thereby gaining $H, the rotor position signal. State observer method generally applies only to the induction electric potential for sine wave of permanent magnet brushless dc motor, and calculation of trival, high performance requirements of microcomputer. So although wholesalemotor.blogspot.com in this way has been put forward, in the late eighty s, many related articles published abroad, but is not very extensive application. Only in recent years, due to the development of the single chip computer technology, especially the high performance DSP (digital 3 phase ac induction motor signal processor) microprocessor application and popularization of this method has a certain applications. Abroad has been using TM S320C31, TM S320C30, ADMC330 DSP chip implements the approach of the permanent magnet brushless dc motor without position sensor control.
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.
Air conditioning switched on, the PTC get indoor to outdoor 220 v alternating current (ac), if the diaphragm normal frequency conversion power, switching power supply output + 5 v to the CPU to work outside the machine, and machine within the CPU to establish communication between inside and outside the machine, the machine have to electric power relay and absorption, make the electric motor fan cover mechanical and electrical source is no longer by PTC, as shown in figure 14. Three minutes later, the machine CPU output "three phase six take" trigger signals and outer fan running, outside the compressor and the fan operation. Machine outside the CPU through the galvanometer coil machine wholesalemotor.blogspot.com plate compressor operation to set up the feedback signal, if the compressor can not start properly, abnormal operation feedback AC lamination synchronous generator signal, output frequency signal to stop 1 minute after the CPU and fan after 30 seconds to stop running. IPM flow or overheating, Vfo end output signal to the machine outside the CPU, outage protection.
The characteristics of the direct torque control is to control the stator flux linkage, is directly under the stator static coordinate system, with space vector concept, by detecting the stator voltage, current, direct calculation under the stator coordinate and control the flux linkage and torque of the motor, torque, high dynamic performance. It does not require the ac motor into equivalent dc motor, and thus eliminate the vector transformation of many complex calculations, it does not need to imitate the ac motor capacitor dc motor control, and thus do not need for decoupling and simplify the mathematical model of ac motor, and just care about the size of the electromagnetic torque and so on in addition to the stator resistance of all control motor parameters change good robustness, the stator flux observer is introduced by magnetic chain model can easily, and conveniently estimate the synchronous speed information, at the same time is also very easy to get torque model, flux model and torque model would constitute the complete motor model, and thus can easily achieve speed spare parts sensorless control, if again set the speed regulator in the system, can be further high-performance dynamic torque control.
To be sure, the direct torque control inverter with different switching device, control method is also different. Depenbrock initially proposed directly from the control theory, mainly in the high voltage, high power and low switching frequency inverters are widely used in the control. Current control method is applied to general inverter is a kind of improvement, suitable for high switching frequency inverters. ABB company first launched in 1995 ACS600 series general inverter direct torque control system, the dynamic torque response speed has reached < 2 ms, when the belt speed sensor PG 0.001% rate of static accuracy of soil, in the case of without speed sensor PG even affected by the change of the input voltage or load mutation, also can be plus or minus 0.1% of the speed control accuracy. Other companies also is trying to target with direct torque control, such as Fuji company FRENIC5000VG7S series high performance electricalmotor1.blogspot.com speed sensorless vector control of general frequency converter, with direct torque control method and difference, but it also has to do the speed control accuracy + / - 0.005%, 100 hz and 800 hz current response speed response and torque control accuracy + / - 3% (PG). Other companies such as Japan's mitsubishi, Hitachi, the latest series of products such as Finland VASON speed sensorless control of similar design, performance have further improved.
In order to grasp the change situation of IC ac signal,can be used with the dB jack multimeter ac electric motor 12v 500w voltage electrical motor 24v to approximate measure of IC.Detection multimeter under ac voltage blocking,pens and insert the dB jack;For no dB jack multimeter,need in pens and concatenated a 0.1 ~ 0.5 u F condenser.The method is suitable for the working frequency is low IC,such as television video amplifier stage,field scanning circuit,etc.Due to acmotortrading.blogspot.com the inherent frequency of the circuit,waveform is different,so the measured data is an approximation,for reference only.
Set the
starting frequency of dc brake and dc brake voltage, should follow the following principles: 3.1 driving system, make sure you are able to eliminate "crawling" phenomenon; 3.2, dc braking motor spare parts current should not exceed the rated current of inverter; 3.3, in the process of the brake system without strong vibration; Dc brake applied occasion. Dc brake is suitable for motor electric the power of 50-100 - kw three-phase asynchronous motor. 4.1 no www.facebook.com/dongfeng.motor impact on the smooth, requirements, parking accurate, such as knitting, sewing, crane, 3 phase ac induction motor hoist, etc; 4.2, before starting brake motor, eliminate irregular rotation caused by external factors, such as a large fan, etc.
1,the seal quality reasons:At the scene of the collapse of the transformer terminals can be found at a time,leakage of oil terminal blocks most of fastening nut loose,install this doesn't mean that it did not tighten,with plane flange rubber gasket,for the first time after fastening tend to loose because of plastic deformation of ac induction motor the rubber gasket,need a second fastening.Transformer and our factory has been running for many years,there is no rubber gasket deformation problem,may explain why only is rubber gasket ageing lose elasticity,reducing the pressure on the surface of the flange connection.According to my years of generator generator set experience in maintenance,air isolation rubber gasket to run more than ten years should not have what problem.
Such as the transformer operation of our factory in nanjing,cichang has more than 20 years,did not find for porcelain set gasket aging oil leakage.Presumably liling porcelain production of transformer set gasket exist quality problems.2,environmental temperature change electricalmotor1.blogspot.com reasons:Refer to instruction for use of current transformer,transformer running environment temperature 40 ℃,the highest temperature is + minimum temperature of 40 ℃.Our factory area this summer outdoor certainly higher than 40 motor vehicle ℃,the highest temperature field measurement of the surface temperature is close to 50 ℃.After each part of the summer heat equipment thermal expansion,due to environment temperature drop after high temperature season,but all kinds of material shrinkage is not consistent with the temperature,cause the leakage of oil from the surface.This point in our plant is particularly prominent.
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.
Unidirectional and bidirectional silicon controlled rectifier thyristor SCR points two kinds,are three electrodes.One-way thyristor cathode (K) and anode (A) and control (G).Bidirectional thyristor is equivalent to two single SCR reverse in parallel.Is one of the one-way silicon anode and cathode in the other side,said the terminal T2,one of the one-way silicon cathode and anode is connected to ac induction motor the other,says the terminal T2,the rest is for control (G).1,single,bidirectional thyristor discriminant: first as A two pole,if it is,but test Pointers are not moving (R x 1 block),may be A,K or G,A unidirectional thyristor (for) can also be extremely T2 and T1 or T2,G motor run capacitor (for bidirectional thyristor).If there are instructions for a single measurement dozens to hundreds of Europe,will be as one-way thyristor.
For K and red pen receive pole,the black pen for G pole,the rest is A pole.If the positive and reverse test instructions are dozens to hundreds of Europe,will be as the bidirectional thyristor.Turn the knob to R * 1 or R * 10 survey,in which www.facebook.com/dongfeng.motor there will be a little older resistance,a red pen is larger for G pole,black pen that provides for the T1,the rest is T2.2,the difference of performance: turn the knob to R x 1 block,for 1 ~ 6 A one-way thyristor,K very red,black pen at the same time through to G,A pole,in keeping the black pen is not out of electrical motor A very great condition disconnect G,pointer should indicate dozens of Europe to euro one hundred,has triggered thyristor at this time,and low trigger voltage (small or trigger current).And then instantaneous disconnect A very connected,pointer should be returned to the up position,suggests that SCR is good.
Seal:I plant oil leakage current transformer are mainly concentrated in four period of current transformer installed in the switching station,four period of current transformer is hunan liling cichang the mid - 90 - products,has been running more than eight years.Current transformer porcelain jacket with electrical motor expander and tank adopts hanging flange connection,this structure has to be eliminated,manufacturers are now used for pressure coil flange connection,compared generator generator set with the hanging type connection,pressure coil flange connection has the advantage that can make the flange surface stress more evenly.
Manufacturers of technical improvement,also can prove the existence of hanging join some shortcomings.Current transformer primary winding through the upper porcelain set of asynchronous motor four terminals,derivation from the scene of the collapse of the transformer terminals can be found at a time,a terminal nanjing cichang the production of transformer and porcelain set of seal,the internal and external two flat pad.And a terminal liling,cichang production of transformer seal only outside a plane pad.Sealing wholesalemotor.blogspot.com structure differences make liling,cichang transformer produced a joint terminal sealing surface oil leakage occurred frequently.But now the liling manufacturer has also made the improvement to this sealing structure,in a terminal seal face to add a seam allowance,o-rings seals,how to be in one step.
A door technology can foothold in society.Maintenance electrician belongs to technical professionals,our country is lack of senior technicians,if electric motor 12v 500w you learn good,also is very promising in the future.Main master electrician: maintenance electrician knowledge and basic skills,indoor wiring installation,grounding device installation and maintenance,repair and maintenance of common transformer,disassembling and maintenance of various commonly used motor,commonly used low voltage apparatus and distribution equipment installation and maintenance,motor control circuit basic installation and maintenance,commonly used machine tools installation and maintenance of electrical wiring,electronic circuit installation and debugging,acmotortrading.blogspot.com electrical control circuit design,programmable power electric motors controller and its application.As to hard to learn,the key see yourself don't work hard,go for it,have confidence in myself,should be able to learn well.
A multimeter is ohm block,the direct measurement of IC on the PCB pin and peripheral components to a direct current 8500w gasoline generator resistance,and compared with the normal data,electrical motor the method to identify and determine the fault.When measuring the attention should be paid to the following three points:(1) measurement to disconnect the power before,to avoid damage when testing meters and components.(2) the multimeter internal electricalmotor1.blogspot.com voltage electric block shall not be greater than 6 v,range it is better to R * 100 or R * 1 k.(3) measurement IC pin parameters,pay attention to the measurement conditions,such as the model to be tested,the electrical motor 24v moveable arm of a potentiometer position related to IC,etc.,also consider the stand or fall of peripheral circuit component.
A 75 kw micro can WIN - G9 inverter commissioning the strange phenomenon.The feeling.Consult factory.Because in a hurry to solve the permanent magnet motor problem,find out,this time without long distance telephone bill is expensive or not.Frequency converter manufacturers and technical personnel reply:this type inverter as the earliest production of frequency converter,a little older no-load current,current fluctuation problem,but belong to normal phenomenon does not affect the use.After the load current will stabilize.Test it with better access to a power motor,you the problem of motor run capacitor the motor,or load problem.Such as motor bearing problem.Problems such as motor and load all ruled out,as long as the inverter output three-phase voltage balance,output current shall not exceed the rated current transducers and can light or load commissioning.
Bad not to drop.As for the proportion of input,output,current problems,due to electricalmotor1.blogspot.com the load is different,it is very difficult to have a fixed ratio.Out of proportion.Don't and proportion problem entanglement.Wanting is also.As long as it is the output three-phase voltage balance,as long as it is in the case of no more than rated current,can bring a load test.Inverter bad not to drop it.Perhaps after loading,the output current will not have motor magnet large fluctuations.Might be normal.Had to take load test,a miracle (surprisingly) :10 Hertz runtime,at 40 a output current,output current is only 7 8 amp.30 hz runtime,60 a output current,input current 25 a.40 hz is run,when output current 100 a,70 amps input current.Running current small,small ripple,is basically stable.Three phase voltage and three phase current balance and relatively stable.Problem has been solved somehow.
Resistance in a circuit with the "R" add digital representation,such as:resistor R1 electric fan motor said number is 1.The main role of resistance in the circuit as the limit of shunt,flow,pressure,offset,etc.1,the parameter identification:the wholesalemotor.blogspot.com unit of resistance is the ohm (Ω),electrical motor multiplying power units are:thousand Ω (K),megohm Ω (M),etc.Conversion method is:1 megohm = 1 million = 1000000 euro resistance parameter annotation method has 3 kinds,namely the direct standard method,color standard method and small electric motors standard method.A,several standard method is mainly used in SMT circuit such as small volume,such as:said 47 472 x 472 Ω (4.7 K); 104 is 100 k
1,the read pointer table accuracy is poorer,but the process of pointer swing is more intuitive,the swing speed range can sometimes more objectively reflect the size of the measured (such as TV measurement data bus (SDL) in the slight shaking when transmitting data);Digital intuitive readings,but electricalmotor1.blogspot.com digital change process seems very messy,not easy to watch.2,pointer table usually has two pieces of batteries,a low voltage of 1.5 V,is a high voltage 9 V and 15 V,the black pens and relative red pens and it is the generator generator set end. Numbers were commonly used a piece of table 6 v or 9 v battery. In resistance,pointer table pens and output current is relatively much larger Numbers table,diesel generating can make the speaker in R x 1 Ω gears a loud sound "da",using R x 10 k Ω file can even light emitting diode (LED).
3,the voltage profile,pointer table resistance relatively smaller,compared with digital meter measuring accuracy is quite poor. Some high voltage micro current situation cannot even measure,because of its resistance to affect the circuit being measured (such as when measuring the acceleration of the TV picture tube voltage level measured value is electrical motor lower than the actual value will be many). The integrity of the digital meter voltage resistance is very big,at least in ohms,little impact on circuit under test. But high output impedance makes it vulnerable to the influence of the induced voltage,in place of some strong electromagnetic interference is measured data may be empty.4,all in all,in a relatively large current measurement of high voltage analog circuits pointer table,such as TV sets,audio power amplifier. In the low voltage low current measurement of digital circuit for digital table,such as BP machine,mobile phone,etc. Is not absolute,can choose according to the circumstance pointer table tables and figures.
(1) under normal circumstances,every 7 days to start the generator no-load commissioning maintenance load of commissioning.5 - lOmin,every time with every month (2) disconnect the output of the generator automatic switch,puts selector switch to manual.(3) check the battery level,not enough level should be equipped with the electrolyte or distilled water,check the liquid proportion,in soda solution soaking and wipe up,coated with vaseline,then tighten the screw connection,and test ac induction motor the battery,battery voltage,and battery charging current at ordinary times.(4) remove the air filter,clean with gas and dust,after the sun to dry.Check the oil oil,such as turbidity or bad generator generator set should be replaced.Diesel engine running after 250 hours,water,oil,diesel oil filter should be changed.
(5) in diesel filter,should check whether the oil valve and valve in full capacity,with or without a fixed screw loose then manual oil pump,eliminate the air in the oil.(6) to check the cooling water plane position at ordinary times,change the water tank in the cooling water,in water,should add rust water.Then the shaking motor winding insulation resistance measurement.(7) to check whether there is oil leakage,the entire unit ground are in good condition,and then do a good job in cleaning unit.(8) open the control cabinet,check the fuse,screw contacts are motor vehicle in good condition,and then close the power control and help keep the oil temperature,water temperature sensor reset,and manual commissioning,oil pressure,output voltage,frequency,etc.(9) manually run 20 ~ 30 minutes,to simulate a power outage of commissioning,and check the ventilation,fire control system whether normal operation.After downtime,place electricalmotor1.blogspot.com selection switch on auto parts,close the output switch.
If the three-phase squirrel cage induction motor,remember is 4 ~ 7 times,but not absolute. But the general requirements of ac induction motor 110kw the motor starting current is no more than the rated current of 2 ~ 5 times. Motor power for more than 30 kw motor is not suitable for frequent start,because more than 30 kw motor starting current is rated current commonly 6 to 12v mini generator motor 7 times,frequent can increase the motor temperature rise,may cause burning motor.Dc motor starting current formula Ist = (Un - Ea)/Ra,n = 0 when starting the armature voltage Ea = magnetic generator an nCe Ф = 0,and Ra is constant,so the rated voltage directly add to both wholesalemotor.blogspot.com ends of the armature,current can reach 10 ~ 30 times the rated current,therefore,usually only a small power dc motor can be used directly to start,the rest are not allowed to start directly.
Maintenance simple electrical control circuit,to each of the electrical components one by one to inspect each wire,usually can quickly find the point of failure.But for complex circuit,often have hundreds of components,thousands of wire,if to examine' method,not only need to spend a lot electrical motor of time,but also easy to leak check.If in this case,according to the circuit diagram,using logical analysis,make concrete analysis of the fault phenomena,to draw suspicious range,improve the maintenance of the targeted,can receive motor run capacitor the accurate and fast effect.
Analysis circuit first,from the perspective of the main circuit,realize the industrial machinery using a few moving parts and electric motor drive,what are related to each motor electrical components,what control adopted,electricalmotor1.blogspot.com and then according to the electric main circuit of the circuit element used text symbols,sex and control requirements,find the corresponding control control circuit.On this basis,combining with the failure phenomena and circuit principle of asynchronous motor work,careful analysis of the screen,can quickly determine the possibility of failure.When fault suspicious range larger,don't need to check step by step,step by step then can be in the range of failure in a check of the intermediate links,to judge the fault occurred where on earth is part of thus narrowing the scope of failure,improve the inspection speed.
Faults exclusion is an important work of maintenance personnel,to eliminate the fault,must know the cause of the failure,more important is can theoretically analysis,solve the fault occurred,should have certain professional theory knowledge,to master the methods of troubleshooting.(a) gradual deduction:if there is a short circuit fault occurs,can be gradually removed part of the circuit to determine the scope of the fault and fault point.(2) adjust the parameter method:in some cases,failure,circuit components is not necessarily bad,line contact is also good,just because of some physical quantity adjustment may be inappropriate or run after a long time,likely due to external factors causing system parameter electrical motor changes or not automatic correction system value,resulting in system cannot work normally,at this time should be adjusted according to the actual circumstances of the equipment.
(3) the principle analysis:according to the principle diagram of the control system,by tracking that is associated with fault signals,the analysis judgment,find out the fault point,and find out the cause of permanent magnet generator the problem.Using this method requires maintenance personnel and unit of the whole system working principle of the circuit have a clear understanding.(11) comparison,analysis,judgement method:it is according to the working principle of the system for controlling the action program and the logical relationship between them,in combination with failure phenomenon,comparison,analysis,and judgment,and reduce the measurement and inspection link,and quickly judge fault range.Above several kinds of commonly used method,can be used alone,also can mix,met the actual electrical fault should be combined with the specific circumstances and flexible application.
Electrical fault phenomenon is varied,the same type of failure may have different failure phenomenon,no similar failure may be the same failure phenomenon www.facebook.com/dongfeng.motor of identity and diversity,complexity to malfunction.Fault phenomena,however,is to find the basic foundation of electrical failure,and is to find the starting point of electrical fault,so be careful observation of fault phenomenon analysis,find out the fault phenomenon in the main,the most typical aspects,find out the failure time,location,environment,etc.A lot of electrical failure,must rely on the professional theory knowledge to really understand have a good grasp of.Electrical maintenance personnel and other workers maintenance personnel in comparison,more theoretical and sometimes no theory to guide a lot of work,it's impossible to be so to have certain professional theoretical high efficiency electric motor knowledge.Maintenance personnel in order to better improve their ability to solve practical problems effectively in the practical work and maintenance level,should constantly strengthen their own professional theoretical knowledge learning and improve the level of operating skills,when electrical fault occurs,can accurately locate the fault,and troubleshoot electrical equipment can steadily run normally.
Now most common triode is powder coating,how to accurately judge the triode three pin which is b,c,e? Triode b very easily measured,but how to judge which is c which is e? Here recommends three methods: the first method: for measuring triode hFE jack pointer table,first measure b pole,throw triode plug into motor vehicle spare parts the socket (b,of course,is very can plug accurate),measure hFE value,then the measuring tube upside down again,the measured values of hFE larger one,each pin insertion position is correct.The second method: to measure without hFE jack table,or is not convenient to insert the socket pipe is too big,can use this method: of NPN transistors,first measure b (the pipe is NPN and PNP b and its feet are easy to measure,isn't it?) ,put table in R x 1 k Ω gear,to connect the red pens and hypothetical e very (note that take the hand don't run into table of red pens and pen or pin),the fan motor black pens and answer the hypothetical c,at the same time hold the table with his fingers tip and the pin,will pick up the pipe,with the tip of your tongue lick a b,the header pointer should have a certain amount of deflection,if all the pens and you answer correctly,the pointer will be bigger,if wrong,the pointer will be smaller,the difference is obvious.
Which can determine pipe c and e.For PNP transistors to black pens and answer the hypothetical e very (hand don't touch the tip or pin),red pens and answer the hypothetical c,at the same time hold the table with his fingers tip and the pin,and then use the tip of the tongue lick a b,if the pens and correctly,header pointer will deflection is larger.Of course when measuring the pens and to discuss the test twice,comparative reading before final decision.This method applies to all appearance triode,convenient and practical.According to the clock deflection amplitude,but also can estimate the pipe amplification ability,of course it is by experience.The third method: first to determine the pipe after the NPN and PNP type a and b,put table at R x 10 k Ω,of NPN transistors,the black pens and connect e,red pens and pick up c extremely,the clock may have some deflection,the PNP transistors,electricalmotor1.blogspot.com black pens and c extremely,red pens and pick up e very,whose hands may have a certain amount of deflection,which in turn would have deflection.This can also determine triode c and e.But for the high pressure pipe,this method is not applicable.
No-load loss is also called the no-load current,is refers permanent magnet motor to the vehicle power supply in the case of no load,consumes the minimum current,no-load current of the on-board power supply generally less than 0.5 amps.This parameter describes motor run capacitor the car power without succeed when used for electrical energy consumption of the size,this value electricalmotor1.blogspot.com as small as possible.To be sure,when the electrical appliances,400v ac motor car power connection to use electrical power and the consumption of electrical energy may be much larger than no-load loss,at this point the car power energy consumption depends on the car power conversion efficiency.
Asynchronous machine positioning for asynchronous motor in the accurate parking problems in the process of operation.Used in the automatic production line.For example: parking in the spindle of high-speed machine tools,because the tool and spindle attaches a convex part of the fixed role,when the motor static,in order to electrical motor smoothly remove cutting tools,and switch to the next tool,bumps on the requirements of spindle always stopped at a fixed location,so that the cutting tool installation smoothly.In the 1970 s to the mid - www.facebook.com/guohong.trading 80 - s,dc electric control system,and the dominant in the 80 s,due to the control theory and method have a breakthrough,make ac motor control gets rapid development,gradually occupied the dominant position.
Research on the positioning control of ac motor has experienced a long stage,the traditional approach is to asynchronous motor use mechanical stop to locate.At present,in the way of positioning used in various industries can be divided into four kinds: mechanical positioning,electric,air,optical positioning.And positioned by way of the electrical control system,and now only Germany has the actual product in the world,in the domestic blank.Because electric positioning control system based on digital general way of working,so high efficiency electric motor can improve the accuracy,is very simple,easy and computer,PLC and other control circuit matching,multiple CNC machine or industrial robot used for the automatic positioning mechanism,scope of application is wide.
