CN2658920Y - Multi-winding high voltage frequency change power source transformer - Google Patents

Abstract

The utility model relates to a multi-winding high voltage variable frequency power transformer, of which the secondary winding of nominal three-phase transformer is designed into 3k groups of three-phase winding with constant capacity and voltage output (k=4, 5, 6 and so on, same as follows), as well as 3k phase power frequency power supply with the output phase angle difference being 60 degrees/k; Meanwhile, wiring terminals applicable to connecting each phase and output terminals are distributed at both sides of the transformer. The utility model is mainly applied to the power transformer of three-phase high voltage variable frequency speed regulator. By three-phase full wave rectification, condenser charge filtration, chopper contravariance, k group concatenation and three groups star connection, the controllable three phase high voltage variable frequency power supply is formed to apply to high voltage asynchronous motor required to regulate the speed during operation.

Description

Many windings high-pressure frequency-conversion power transformer

Affiliated technical field

The utility model relates to a kind of high-pressure frequency-conversion power transformer, particularly a kind of conventional three phase worker power is transformed to the phase-shifting rectifier transformer that three groups of standard type 3k export mutually, belongs to power transmission technology field.The power transformer that is used for high-voltage frequency conversion and speed-adjusting device.

Background technology

For energy-conservation and speed governing, many high-power high voltage asynchronous motors all need to adopt high-voltage frequency conversion and speed-adjusting device, and traditional high-pressure frequency-conversion technology all exists some defectives:

A kind of method is to export one group of three-phase low pressure by high voltage source through step-down transformer, through the lower pressure rectifier inversion, obtains the frequency conversion high pressure with step-up transformer again.Big, the complex structure of low-tension current in the middle of it exists, efficient are low, poor reliability, harmonic wave is big and need two shortcomings such as transformer.

Another kind method be directly by high voltage source through commutation inversion.Be difficult to bear technical reasons such as high backward voltage owing to high power device, maximum output voltage can only reach 2.3kV up till now, and the input and output harmonic wave is big, output voltage fluctuation rate dv/dt height, is very much unfavorable to the motor safe operation.

Also having a kind of method is three-level frequency-converter, rectifier transformer adopts two groups of three-phase outputs, and the output line voltage level number is 3, and output voltage contains very high high order harmonic component, make that electric moter noise increases, heating is serious, and the highest output AC voltage only reaches 4.6kV at present.

Summary of the invention

Above-mentioned defective at existing converter technique existence, the purpose of this utility model, be that a kind of three groups of 3k phase phase-shifting rectifier transformers that mainly are applicable to the type frequency conversion of units in series voltage with multiple levels source are provided, make this frequency conversion only need a transformer just can finish, rectification, inversion are carried out in each group output respectively, electric current and voltage in its process is all lower, and the series connection output voltage can be very high.The line voltage level number of this frequency conversion output is that (2k+1) is individual, and k is big more, the out-put supply waveform approaches sine wave more, output harmonic wave is more little, output voltage fluctuation rate dv/dt is low more.Because transformer is three groups of standard type 3k phase 6k pulse wave rectifier outputs, makes that the harmonic current of transformer feedback electrical network is also more little.

The technical solution of the utility model is: the three-phase heart type structure that adopts unshakable in one's determination.Interior loop is a former limit input winding, can be the Δ connection, also can be the Y connection.Exterior loop is a secondary output winding, have 3k wait capacity, etc. voltage export winding and arrange coiling and mutually insulated from top to bottom; 3k output winding is divided into three groups, every group k, k have during for odd number 1 y connection 0 ° of output of not phase shift winding, (k-1) individual output winding adopts the extend-triangle phase shift in addition; When k was even number, k output winding all adopted the extend-triangle phase shift; K the mutual phase angle difference of three-phase output winding after outside three is connected equals 60 °/k.

3k output winding all used the Copper Foil coiling, and each winding is around one section, and the Copper Foil width equates that thickness is pressed $\mathrm{\δy}=\sqrt{3}\mathrm{\δz}$ (wherein δ y is the thickness of phase shift winding Copper Foil, and δ z is the thickness of main winding Copper Foil, has the copper thickness of 0 ° of output winding also to be δ y).Intersegmental stopping insulated so that satisfy the insulating requirements of the output HIGH voltage of k output voltage after the commutation inversion overlapped in series.The turns calculations of each winding is with general extend-triangle phase shift computational methods.

3k output winding all is placed on input one side from main winding (or the y of 0 ° of output winding connects asterism) around, top, the head end of the end of main winding and phase shift winding is connected to cause after finish winding inside imports a side.The end of phase shift winding (or output of 0 ° of output winding) is placed on output one side; The equal round numbers circle of each main winding, 0 ° of output winding of each phase shift winding and y connection is all few around half turn.

The beneficial effects of the utility model are that the utility model is exported three groups of standard type 3k cross streams power supplys, match with high-voltage frequency conversion and speed-adjusting device, through 3k three phase full wave rectification, capacitor charging filtering, copped wave, the folded wave scale number of series connection formation is the phase of k then, and three groups of y are connected to form the three-phase high-voltage variable frequency power supply.Like this, both made the harmonic current of transformer feedback electrical network very little, the reverse voltage that rectification, inverter are born is lower, the forward conduction electric current is less; The level number of output line voltage is individual up to (2k+1), make that frequency conversion output voltage height, output voltage fluctuation rate dv/dt are low, output waveform approaches sine wave, other frequency conversion mode all can be readily solved because of the high problems such as electric motor overheating, noise and torque pulsation that cause of output harmonic wave.

Description of drawings

Below in conjunction with drawings and Examples the utility model is described further.

Fig. 1 is the structural representation of the utility model k=5,

Fig. 2 is the left side view of Fig. 1,

Fig. 3 is the rearview of Fig. 1,

Connection, vector and the phase shifting angle schematic diagram of 15 output windings when Fig. 4 is the utility model k=5,

Connection, vector and the phase shifting angle schematic diagram of 18 output windings when Fig. 5 is the utility model k=6,

In Fig. 1～3,1. iron core, 2. former limit input winding, 3. secondary output winding, 4. input power connection end, 5. output power connection end, 6. output splicing ear.

Among Fig. 4, Fig. 5, A, B, C are input terminal, the umber of turn when the W Δ is former limit Δ connection.A1, b1, c1, a2, b2, c2 ..., a3k, b3k, c3k (3k=15 among Fig. 4,3k=18 among Fig. 5) are secondary 3k group lead-out terminal.

Among Fig. 4, Wy3, Wy8, Wy13 are the number of turn of 0 ° of output winding of y connection, Wy1～Wy15 (not containing Wy3, Wy8, Wy13) is the phase shift umber of turn of phase shift output winding, and Wz1～Wz15 (no Wz3, Wz8, Wz13) is the main winding number of turn of each phase shift output winding correspondence.

Among Fig. 5, Wy1～Wy18 is the phase shift umber of turn of 18 phase shift output windings, and Wz1～Wz18 is the main winding number of turn of phase shift output winding correspondence.

Embodiment

Shown in Fig. 1～4, unshakable in one's determination 1 adopts the three-phase heart type structure, and former limit input winding 2 and secondary output winding 3 adopt resin-cast, F class F insulation.2 is interior loop, rated capacity 1600kVA, and rated voltage 6.3kV, the Δ connection, 4 are input power connection end; 3 is exterior loop, forms coiling from top to bottom, mutually insulated by 15 each 106.7kVA of rated capacity, rated voltage 690V windings; 15 output windings are divided into three groups, every group 5 of I, II, III, and the phase shift angle is respectively+24 ° ,+12 °, 0 ° ,-12 ° and-24 °, wherein 0 ° of winding y connects, and other is the output winding of extend-triangle phase shift.

The design of iron core parameter, W Δ choose same conventional transformer, Wy ₃: W Δ=690: 6300 √ 3, Wy ₃=Wy ₈=Wy ₁₃, calculating rounds and is the electromagnetism number of turn, and reality is got half turn less.

± 24 ° of phase shift umber of turn Wy ₁=Wy ₅=Wy ₆=Wy ₁₀=Wy ₁₁=Wy ₁₅≈ 0.21Wy ₃, round back reality and get half turn less, corresponding main winding number of turn Wz ₁=Wz ₅=Wz ₆=Wz ₁₀=Wz ₁₁=Wz ₁₅≈ 1.41Wy ₃, round.

± 12 ° of phase shift umber of turn Wy ₂=Wy ₄=Wy ₇=Wy ₉=Wy ₁₂=Wy ₁₄≈ 0.62Wy ₃, round back reality and get half turn less, corresponding main winding number of turn Wz ₂=Wz ₄=Wz ₇=Wz ₉=Wz ₁₂=Wz ₁₄≈ 0.72Wy ₃, round.

Wy ₁～Wy ₁₅Winding is by specified fundamental current 89.25A, and main winding is by specified fundamental current 51.53A.15 output windings select around 15 sections, each winding altogether that the Copper Foil width is equal, thickness δ for use _y: ${\mathrm{\δ}}_z=\sqrt{3}:1$ (wherein δ y is the thickness of phase shift winding Copper Foil, and δ z is the thickness of main winding Copper Foil).Layer insulation is a resin prepreg cloth, and the ectonexine insulation of section insulation, overhang insulation and coil is the reinforced epoxy resin.

The output winding of 12 band phase shift windings is first separately around main winding, back around the phase shift winding, the two is connected and draws after finish this section winding inside, with the top of the top of 12 main windings and 30 ° of windings altogether 27 cause input one side as output splicing ear 6, the end of each phase shift winding and 0 ° of winding as output power connection end 5 altogether 15 cause output one side.

Claims (2)

1. the power transformer of winding high-pressure frequency-conversion more than a kind, the three-phase heart type structure that adopts unshakable in one's determination, it is characterized in that: interior loop is former limit input winding, exterior loop is a secondary output winding, have 3k wait capacity, etc. voltage output winding arrange coiling from top to bottom, and mutually insulated, 3k output winding is divided into three groups of I, II, III, and every group of k, k have 0 ° of output of not phase shift winding of 1 y connection, k-1 output winding employing extend-triangle phase shift in addition during for odd number; When k was even number, k output winding all adopted the extend-triangle phase shift; K the mutual phase angle difference of three-phase output winding after outside three is connected equals 60 °/k.

2. many windings high-pressure frequency-conversion power transformer according to claim 1, it is characterized in that: 3k output winding all connects asterism from the y of main winding or 0 ° output winding and is placed on input one side around, top, the head end of the end of main winding and phase shift winding is connected and causes input one side after finish winding inside, and the output terminal or 0 ° of output winding of phase shift winding is placed on output one side; The equal round numbers circle of each main winding, 0 ° of output winding of each phase shift winding and y connection is all few around half turn.

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