Say simply, hand in hand in transducer to need to use too much cell, bad to control, and hand in make use component continuously little, control is simple, use mostly at present so hand in the transducer that makes a structure continuously.

 

 

1, the development of transducer should experience as much slowly the process of advance gradually, original transducer is not to use this kind to hand in hand in continuously: Communication becomes straight to flow to change again after that communicate this kind of develop to attack, hand in directly however, without intermediate dc link. This kind of transducer makes hand in hand in transducer, at present this kind of transducer is in exceed timing of high-power, low speed to have application. Its output frequency limits to be: 0-17 (1/2 – 1/3 inputs voltage frequency) , cannot satisfy the requirement of a lot of application so, and there is not IGBT at that time, have SCR only, applied range is so narrow.

 

 

Hand in hand in transducer its job principle is three-phase labour frequency power source passes a few groups of photographs to accuse switch control to produce place to need power supply of transformation frequency conversion directly, its advantage is efficiency tall, energy is OK and convenient return electrified wire netting, the highest frequency that its biggest drawback outputs must be less than 1/3 of frequency of input power source or 1/2, output weaveform otherwise too poor, electric machinery generation shakes, cannot work. Reason is handed in hand in transducer up to now circumstance of timing of confine low rotate speed, restricted its scope of application greatly consequently.

 

 

Matrix type transducer is one kind is handed in hand in direct transducer, receive the switch between three-phase input and output directly by nine blast composition. Matrix transformer does not have intermediate dc link, output is comprised by 3 n, harmonic content is smaller; Its power circuit is simple, compact, can output frequency, amplitude to reach phasic the sine load voltage that can accuse; The power input factor of matrix transformer can accuse, can work in 4 quadrant.

 

Although matrix transformer has a lot of advantages, but change in its in shedding a process, do not allow to exist two switch guide at the same time the simultaneous phenomenon that perhaps closes, it is more difficult that implementation rises. Matrix transformer is the biggest output voltage ability is low, parts of an apparatus bears voltage is tall also be this kind of transformer a very big drawback. In applying in wind-force to generate electricity, as a result of the input of matrix transformer output indissolubles Ou, the asymmetry that no matter be laden,still is power source side namely can affect another side. Additional, the input end of matrix transformer must receive filter wave capacitance, although the capacity of its capacitance is compared,hand in orthogonal among store can electric capacity is small, but because they are alternating current look, should bear the alternating current of switch frequency, its volume is not minor.

 

 

 

Hand in – making frequency conversion is direct frequency conversion, little a link, but amount of used parts of an apparatus is very much, the need of three-phase canal of 36 brilliant brake, control is complex. Our teacher says whose attune connected 36 pipe to be able to graduate instantly for fun. Still have hand in – hand in frequency conversion to be able to reduce section frequency toward labour frequency only, move the 1/3-1/2 of labour frequency commonly, about the same 20Hz.

 

2, we change this kind of communication straight to flow to change again after that communicate this kind of transducer to make hand in hand in transducer continuously, cent is two kinds, one kind is to hand in the straight profiling that make report, additionally one kind is to meet the straight flow pattern that make report. Among them former and extensive use, present general transducer uses this kind of develop to attack namely. Its characteristic is: To electroanalysis capacitance stores among offer bus voltage, class uses diode not to accuse rectification before, simple and reliable, inversion uses three-phase PWM modulation (at present modulation algorithm is dimensional voltage vector) . Electroanalysis as a result of what used certain capacity capacitance, dc generatrix voltage is so stable, the switch that should control good inversion IGBT only right now is ordinal (output appearance sequence, frequency) and occupy sky comparing (output voltage size) , can acquire very advantageous control character.

 

Handing in — straight — to hand in transducer is first commutator of alternating current classics first rectification becomes dc, shed intermediate circuit to have flowing filter wave to the output of rectification circuit continuously, repass inverter turns this dc electric current into the alternating current with frequency and alterable voltage.

 

Hand in hand in transducer to be able to divide the profiling that it is report and electric flow pattern again continuously two kinds, because control all sorts of elements such as method and hardware design, voltage inverter application is wider. Flow pattern hands in traditional report to hand in transducer to use nature to change adoption brilliant brake canal to regard power as switch continuously, inductance of its dc side is costlier, and in applying at timing of double make a present of, had been in synchronous fast when need changes galvanic way, in low turn the performance below the condition of poor frequency is poorer also, generate electricity in wind-force of asynchronous of double make a present of what medium applying is not much. Use electric profiling to hand in hand in transducer continuously device of frequency conversion of this kind of commutate has a structure content of simple, harmonic factor of power of little, calm rotor is adjustable wait for exceedingly good characteristic, OK and apparent ground improves quality of the moving condition of dynamo of double make a present of and output electric energy, and this structure passes capacitance of dc generatrix side realized the depart of net side and rotor side completely. Electric profiling makes the magnetic field of stator of dynamo of double make a present of that makes transducer continuously directional vector controls a system, came true to be based on fan most have rendered great service mixes the dynamo that high-power dot dogs to be controlled without the solution Ou of result, it is the direction of a delegate that at present wind-force of gearshift constant frequency generates electricity.

 

 

 

In addition, return those who have a kind of parallel connection to hand in hand in inverter develop to attack continuously structure. The main idea of this kind of structure is hand in through the straight flow pattern that make report makes parallel connection of transducer of the straight profiling that make report with, electric current inverter is made give priority to inverter to be in charge of power transmitting, voltage inverter serves as complementary inverter is in charge of compensating harmonic of electric current inverter. This kind of structure advocate inverter has inferior switch frequency, complementary inverter has inferior switch electricity. Alexandrine face mentions hand in inverter of the straight profiling that make report to be compared, this develop attacks the structure has low switch loss, the efficiency of whole system is taller. Its defect also is clearly, the use of much power electronic parts brings about the rise of cost and more complex control algorithm, utilization rate of voltage of this kinds of structure is additionally lower.

 

 

3, although hand in — straight — to hand in transducer to have output frequency factor of tall, power is advanced advantage, but hand in — straight — to hand in transducer to still put the issue that is in a lot of waiting for to improve:

 

(1) electronic parts of power of current high-power tall voltage lies development period, GTO component side is faced fall into disuse, IGBT, IGCT still waits for maturity;

 

(2) use IGCT (or GTO) , the convertor of IECT, breakdown of parts of an apparatus creates the protection of direct short circuit or difficult problem; If convertor of power source side produces direct short circuit to be able to cause short circuit of electrified wire netting, so converter must use tall leakage to fight input transformer, general requirement 15% , be as high as 20% even;
 

(3) bring down of ability of the overload when handing in — straight — to hand in transducer low frequency to move, move in halve of ability of overload of the transducer when 5Hz is the following commonly;

 

(4) the Du/dt of voltage change ratio that hands in — straight — to hand in transducer to output weaveform of PWM modulation voltage is very tall, cause the insulation exhaustion of electric machinery and electric equipment easily to injure; When output lead is longer, in all modular reflex voltage can produce very tall tension in electric machinery side, if be the convertor of two n, double the peak value of this voltage is volts d.c. , if be the convertor of 3 n, the peak value of this voltage is 3 times of intermediate half voltage;

 

(5) hand in — straight — to hand in transducer PWM modulation to will produce the problem such as electric current of harmonic, noise, axis.