CN201191747Y - High-voltage line de-icing apparatus - Google Patents

Abstract

The utility model relates to a de-icing device for a high voltage line, which comprises the following parts: a phase-shifting isolation transformer (ST) for the input of the power supply, a power electronic frequency converter (PE) and a three-phase resonant capacitor reactor (RC), wherein the input of a resonant frequency converting de-icing device with high voltage and high-power is the phase-shifting isolation transformer, each secondary winding output of the transformer is connected with a corresponding power unit of the power electronic frequency converter, eight power units in each phase are connected in series, and the output ends are A', B', C', the three-phase input ends of the resonant capacitor reactor are respectively and correspondingly connected with the output ends A', B', C' of the power electronic frequency converter, the output ends A, B, C of the three-phase resonant capacitor reactor are directly connected with a de-icing line. According to the principle that the skin effect occurs when the wire is in high-frequency, the frequency of carrying current of the line is improved from 50Hz to 1000-1800Hz, and the resistance of the corresponding line is increased by about five times, and the current transmitted by the line and the damages of over-current of the line are reduced under conditions with the same ice melting power.

Description

The high-tension line deicer

Technical field

The utility model relates to the research of the deicing supply unit of high pressure resonant vibration frequency conversion principle.The technical field that belongs to electric deicing.

Background technology

The sleet and the freezing disaster that continue tend to make electric power system to get into a difficult position, and iron tower collapses, circuit is stopped transport, grid disconnection, and these electric power dangers make the people's normal life and economical operation suffer grave danger.The main reason of these dangers is circuit icing, so must take some deicing measure when the icing of circuit arrives certain thickness.In existing deicing technological means, the means efficient of the artificial deicing of machinery is low, the risk factor height, and the cycle is long, is difficult to large tracts of land and promotes; Adopting the method for new material lead promptly to increase cost also often can not excellent popularization, particularly in old circuit; Original circuit great current deicing method requires the integrality of circuit, and the electric energy that consumes is many; 2 circuits ice-melts simultaneously often of direct current ice-melting method, relative time is long when normal three-phase operation line ice-melting, complicated operation.The resonance skin current method of the bright proposition of we is utilized the kelvin effect under the lead high frequency situations, by improving the frequency of transmission current, make the all-in resistance of circuit increase, promptly under identical ice-melt power condition, the electric current that circuit transmits can reduce, and reduces the overcurrent harm of circuit; Simultaneously, by piling at the junction of power electronics converter plant and circuit series capacitor, make the equivalent inductance of it and circuit under certain frequency, realize series resonance, the final equivalence of circuit is a pure resistive loads, can under the situation of identical ice-melt power, only transmit active power like this, also need transmit reactive power unlike original great current deicing method, the power minimum that needs transmission is comparatively speaking than great current deicing method efficient height.

Summary of the invention

The purpose of this utility model provides a kind of high-tension line deicer, be intended to use kelvin effect and series resonance principle to realize circuit deicing scheme, realize that the circuit ice melting current significantly reduces under the equal heating power, can make simultaneously the circuit transmission power only be active power, improve line ice-melting efficient, reduce operating cost, and supporting high-power circuit deicer is provided, for this deicing scheme provides the ice-melt electric energy.

Technical scheme: high voltage high power resonant vibration frequency conversion deicing method of the present utility model is the electric current de-icing method based on kelvin effect and series resonance principle, under situation about having a power failure, the three-phase conducting wire of circuit one end by the shorting stub short circuit, promptly the whole three-phase circuit is considered as a threephase load, three-phase short circuit point is as the neutral point of load; And add the high voltage high power resonant vibration frequency conversion deicing device at the other end of circuit, and series resonance capacitor heap between power electronics converter plant and circuit, 1000～1800Hz high-frequency current of this device output flows through this circuit; Behind 1000～1800Hz high-frequency current of this method by feeder apparatus output on the line, the resonant capacitor of the equivalent inductance of DC ice-melting and high voltage high power resonant vibration frequency conversion deicing device is in device output frequency point place series resonance, make that whole circuit and the equivalence of device loop are the pure resistive loads of heating, the i.e. active power that only consumes of the transmission power of circuit in the case for ice-melt, the resistance value of circuit is significantly increased, while also makes the heating part of circuit concentrate on the near surface of circuit, and two kinds of effects can significantly be accelerated the speed of the ice-melt of circuit.

Deicer comprises with the lower part and forming:

A phase shift isolating transformer that is used for power supply input, the once input winding of this isolating transformer is 1, secondary output winding is 24, the input of corresponding 24 power cells of the output of secondary winding, wherein A, B, C three-phase each to 8 power cells should be arranged;

A power electronics converter plant, this converter plant adopts cascade connection type topological structure, whenever is made up of 8 power unit cascades, and star-like connection is exported; Power cell adopts three-phase not control the rectification input, electrochemical capacitor DC filtering, the 2H bridge output that insulation gate pole bipolar transistor IGBT is formed; Each power cell of power electronics converter plant inserts the alternating current of the three-phase rated line voltage 720V/50Hz of the corresponding secondary winding output of phase shift isolating transformer, in each power cell, set up independent direct voltage then through rectifying and wave-filtering, last each power cell is realized the conversion of direct current-high-frequency ac by pulse modulation technology, and the cascade by 8 power cells of every phase promptly can produce the specified 10KV/ of three-phase (1000～1800Hz) high-frequency alternating current;

A three-phase resonant capacitor heap, its basic composition is the noninductive big current film capacitor of 100A/3000V, connection in series-parallel by them connects the withstand voltage and current carrying capacity that improves electric capacity, realizes the actual resonant capacitor heap under the high-voltage great-current operating condition

The input of high voltage high power resonant vibration frequency conversion deicing device is the phase shift isolating transformer, and the output of each winding of transformer secondary connects with corresponding power electronics converter plant power cell, every 8 cascade of power units connections in mutually, and output is A ', B ', C '; The three-phase input end of resonant capacitor heap is connected with A ', B ', C ' the three-phase output correspondence of power electronics converter plant respectively, and output A, B, the C of resonant capacitor heap directly are connected with the deicing circuit.

Frequency changing power device will adopt the frequency conversion mode of high-voltage alternating 1-direct current-high-voltage alternating 2, and high-voltage alternating 1 is a power frequency supply, and high-voltage alternating 2 is output high frequency deicing power supply.The power frequency supply input is by rectification behind the isolating transformer, and filtering is middle DC link again, and DC link is through high-frequency PWM inversion output high frequency deicing power supply, after one group of series resonance capacitor output (seeing accompanying drawing 1).The basic principle of deicing still relies on electric current to flow through circuit and makes the resistance heating ice-melt, but the frequency electric current increases many times among the present invention, utilizes skin effect of line that resistance per unit length is significantly increased, and changes circuit heating environment, accelerates ice-melt speed.Simultaneously in order to reduce the power output of deicing supply unit, according to the series resonance principle, seal in resonant capacitor and and the equivalent inductance of circuit at deicing supply unit output frequency point resonance, be the circuit equivalence pure resistor load, make circuit only carry active power.

Description of drawings

Fig. 1: the illustraton of model of deicing supply unit;

Fig. 2: cascade connection type deicing supply unit topological diagram;

Fig. 3: power electronics converter plant power cell topological diagram;

Fig. 4: the kelvin effect principle schematic of lead;

Fig. 5: series resonance schematic diagram;

Fig. 6: three-phase line ice-melt winding diagram;

Fig. 7: uniline ice-melt winding diagram;

Fig. 8: the internal series-connection connection layout of uniline ice-melt supply unit;

Symbol description

ST: the phase shift isolating transformer,

PE: the power electronics converter plant,

RC: the resonant capacitance heap,

A, B, C: the three-phase output end of high voltage high power resonant vibration frequency conversion deicing device,

L1～L24: phase shift isolating transformer secondary winding 1～phase shift isolating transformer secondary winding 24,

CellA1～cellA8:A phase power cell 1～A phase power cell,

CellB1～cellB8:B phase power cell 1～B phase power cell,

CellC1～cellC8:C phase power cell 1～C phase power cell,

D1～D6: the inner three-phase of power cell is not controlled the rectifier bridge diode,

Q1～Q4: the inner 2H bridge of power cell IGBT,

Cap1～Cap3: the inner DC filter capacitors of power cell,

R1～R3: the balance of voltage resistance of the inner DC filter capacitors of power cell,

I (t): the electric current that flows through in the lead,

φ (t): near the magnetic flux the lead,

δ: the skin depth of lead under kelvin effect,

L: the circuit equivalent inductance,

C: seal in resonant capacitor,

R: the circuit equivalent resistance,

AC: high-frequency ac power,

AC Source: high-frequency ac power,

Cap11～Cap13: the resonant capacitor heap that A, B, C seal in respectively mutually during the three-phase line deicing,

Capd: the resonant capacitor that seals in during the uniline deicing,

Cap21～Cap23: three resonant capacitor heaps that seal in during the uniline deicing,

L ": circuit equivalent inductance during the uniline deicing,

R ": circuit equivalent resistance during the uniline deicing,

A1, B1, C1: the high voltage high power resonant vibration frequency conversion deicing device is by three high frequency electric sources of phase-splitting control equivalence during the uniline deicing.

Embodiment

Be electric current de-icing method, be applicable to the electric current heating ice-melt under the circuit ice coating situation based on kelvin effect and series resonance principle; Under situation about having a power failure, the three-phase conducting wire of an end of circuit by the shorting stub short circuit, promptly is considered as a threephase load to the whole three-phase circuit, three-phase short circuit point is as the neutral point of load; And add the high voltage high power resonant vibration frequency conversion deicing supply unit at the other end of circuit, make the high-frequency current of 1000～1800Hz of this device output flow through this three-phase or uniline; This method can make the resistance value of circuit significantly increase by after adding 1000～1800Hz high-frequency current on the line, and the while also makes the heating part of circuit concentrate on the near surface of circuit, and two kinds of effects can significantly be accelerated the speed of the ice-melt of circuit; This method also comprises in addition, the resonant capacitor of the equivalent inductance of DC ice-melting and high voltage high power resonant vibration frequency conversion deicing supply unit piles up device output frequency point place series resonance, make whole circuit and device loop equivalence be the pure resistive loads of heating, promptly the transmission power of circuit only is the active power of ice-melt consumption in the case.

The high-tension line deicer comprises with lower member and forming:

A frequency changing power device, this device adopts cascade connection type topological structure, 8 power unit cascades of every phase; Power cell adopts three-phase not control the rectification input, the electrochemical capacitor DC filtering, the output of 2H bridge, device is by the alternating current of the specified 10KV/50Hz of isolating transformer input three-phase, in each power cell, set up independent direct voltage then, the conversion that utilizes the PWM technology to realize directly-hand at last promptly can produce the specified 10KV/ of three-phase (1000～1800Hz) high-frequency alternating current.

A three-phase resonant capacitor heap, its three-phase input end are connected with A, B, the C three-phase output correspondence of frequency changing power device respectively, and the output of resonant capacitor heap directly is connected with circuit; The basic composition of resonant capacitor heap is the noninductive big current film capacitor of 100A/3000V, by their connection in series-parallel connection, can realize the operating condition of high-voltage great-current.

This method is the electric current de-icing method based on kelvin effect and series resonance principle, under situation about having a power failure, the three-phase conducting wire of circuit one end by the shorting stub short circuit, promptly is considered as a threephase load to the whole three-phase circuit, and three-phase short circuit point is as the neutral point of load; And add the high voltage high power resonant vibration frequency conversion deicing device at the other end of circuit, and series resonance capacitor heap between power electronics converter plant and circuit, the high-frequency current of this device output 1000～1800Hz flows through this circuit; This method is by after adding 1000～1800Hz high-frequency current on the line, the resonant capacitor of the equivalent inductance of DC ice-melting and high voltage high power resonant vibration frequency conversion deicing device is in device output frequency point place series resonance, make that whole circuit and the equivalence of device loop are the pure resistive loads of heating, the i.e. active power that only consumes of the transmission power of circuit in the case for ice-melt, the resistance value of circuit is significantly increased, while also makes the heating part of circuit concentrate on the near surface of circuit, and two kinds of effects can significantly be accelerated the speed of the ice-melt of circuit.

The high-tension line deicer is described:

Show that as accompanying drawing 1 the high voltage high power resonant vibration frequency conversion deicing device comprises phase shift isolating transformer, power electronics converter plant, detection control system, resonant capacitor heap.The phase shift isolating transformer is mainly the power supply that the power electronics converter plant provides isolation, can reduce harmonic wave by its special processing.The power electronics converter plant is by AC/DC, DC/AC two parts, and the AC/DC part becomes direct current to the industrial frequency AC rectifying and wave-filtering, and DC/AC partly is reverse into high-frequency ac to DC PWM, its concrete form-cascade connection type (accompanying drawing 2).Series resonance capacitor and equivalent line inductance constitute the LC series resonant tank, and its appearance value is determined according to circuit Equivalent Model inductance value and resonance frequency, and its withstand voltage is determined by the resonance maximum voltage value.Detect the control core of control system, by according to special algorithm control power electronics converter plant the power supply of power frequency being become the high frequency electric source of 1000～1800Hz after the image data as device.

Isolating transformer adopts the structure of prolonging the limit phase shift, common name ZIGZAG transformer.The primary side of this transformer has only a winding, inserts three-phase 10KV/50Hz AC power, and specified power is 10MW; Secondary winding has 24 three-phase output windings, and the voltage of output is three-phase 720V/50Hz alternating voltage, and the output rated power of each three phase winding is 415KW.In accompanying drawing 2,8 windings in winding L 3, L6, L9, L12, L15, L18, L21, this team of L24 power cell 1～power cell 8 of corresponding A phases respectively exchange the input windings, and winding L 2, L5, L8, L11, L14, L17, L20, L23 and winding L 1, L4, L7, L10, L13, L16, L19, L22 corresponding B, C power cell mutually respectively.Simultaneously, adopt phase shift technology to handle between each winding of homophase one team, it is the angle of mutual phasing 60 °/8 between the adjacent winding output voltage, as A phase winding L3 than winding L 6 leading 7.5 °, and winding L 6 is than winding L 9 leading 7.5 °, so go down, B, C phase same treatment are formed the many output isolation transformers that prolong the limit phase shift;

The electronic power inversion converter plant, show as accompanying drawing 2, this inverter three-phase output, every by 8 identical power cell (cellA1 in the accompanying drawing 3～cellA8) form, 8 power cells are connected in series in the homophase, be that the output 2 of first power cell and the output 1 of second power cell are connected, the output 2 of second power cell is connected with the output 1 of the 3rd power cell then, so go down, the output 2 of the 8th last power cell is as the inversion output of corresponding phase, in addition, 1 of the output of first power cell of three-phase is connected with each other as the suspension neutral point.The basic composition of the power cell of accompanying drawing 3 is: three-phase is not controlled rectifier circuit (6 high-voltage great-current rectifier diode D1～D6 form), capacitor filtering circuit (Cap1～Cap3, R1～R3, wherein the resistance of resistance is identical, realize three capacitor voltage equalizings), (4 full control power tube Q1～Q4 form the 2H bridge, the inverter circuit of device choosing insulation gate pole bipolar transistor-IGBT).Three-phase is not controlled the winding of the input connection isolating transformer secondary side correspondence of rectifier circuit, and its output connects the capacitor filtering circuit, connects the 2H bridge inverter circuit behind the capacitor filtering and exports single-phase high frequency voltage.After the series connection of 8 power cells of every phase, be exportable high-power high frequency voltage electric current by core controller control electronic power inversion device.

Detecting control system mainly is to control the electronic power inversion converter plant, and it comprises core processor DSP (digital signal processor)-TMS320F2812, the pwm output processor FPGA (gate array can be edited in the scene)-EP2C8T144 that data acquisition, control algolithm are calculated.

The deicing supply unit mainly also has some special control algolithms, as the adaptive control of phase-splitting control, frequency.Phase-splitting control, promptly under known power unit stable DC voltage condition, by detecting the size of phase current, and then adjust the modulation ratio or the pilot angle of each phase inverter correspondence of circuit, promptly determine output voltage, finally make three-phase balance by the relation of output voltage electric current.The adaptive control of output current frequency, its fundamental method is exactly that frequency is progressively changed by accuracy of detection in certain scope, the electric current situation of change of while Monitoring Line circuit, adjust output frequency according to line current amplitude phase place, make equivalent inductance and series resonance capacitor at output frequency place resonance, improve the circuit transmission power.

The series resonance capacitor heap adopts metallized noninductive film capacitor.The capacitor elementary cell is specified alternating voltage 3000V, specified alternating current 100A's is single, form one group by such 60 same capacitor series connection, pile with the resonant capacitor of a synthetic phase after five groups of same series capacitor bank parallel connections then, three-phase is with three heaps.

Concrete operation has following three kinds of execution modes:

First execution mode:

Three-phase deicing simultaneously.The consideration circuit is a three phase symmetry load, and as shown in Figure 6, the place connects high pressure resonant vibration frequency conversion deicing device in the middle of the circuit of 100KM, and the end of two 50KM connects by shorting stub, and every i.e. equivalence of circuit becomes two resistive loads.The capacitance Cap21=Cap22=Cap23 of three-phase capacitor, the frequency f 1=f2=f3 of three phase mains.Such connection type can reduce the distribution influence of line parameter circuit value.In addition, three-phase deicing simultaneously can be saved the ice-melt time, improves ice-melt efficient.

Second execution mode:

The uniline deicing.As shown in Figure 7, deicer power end ground connection, the resonant capacitor outlet is connected in the middle of the 300KM circuit, and deicing supply unit, icing circuit, the earth constitute the loop, and this operational mode is particularly suitable for the ground wire of transmission line or the contact line deicing of electric railway.At this moment, equivalent capacitance value is after 8, three capacitors in series of the back panel wiring of deicing supply unit such as accompanying drawing $C^{\′\′}=\frac{1}{3}C,$ By $f=\frac{1}{2\mathrm{\π}\sqrt{L^{\′}{C}^{\′}}},$ Can get L "=3L; R '=3P ₁/ I=3R (f); (wherein L, R (f) is the 50km line parameter circuit value), the benefit of doing so just can make full use of the power output of device, and the circuit when making the single ice-melt is increased to three times when using a phase power supply, improves the time efficiency of ice-melt operation.Certainly, device must adopt the method for phase-splitting control under such mode of connection, otherwise when press the method output of three-phase output voltage, the output of device voltage only is zero.

The 3rd execution mode:

Uneven phase-splitting control ice-melt.Be used for the three-phase non-symmetrical line, can effectively suppress three alternate imbalance problems.As shown in Figure 6, the mode of connection is with first execution mode.Difference is that the three phase mains of converter plant output f1, f2, f3 does not frequently wait, and capacitance Cap21, the Cap22 of each resonant capacitor that is in series, Cap23 also can be unequal.

Claims (1)

1. high-tension line deicer is characterized in that this device comprises with the lower part to form:

A phase shift isolating transformer (ST) that is used for the power supply input, the once input winding of this isolating transformer is 1, secondary output winding is 24, the input of corresponding 24 power cells of the output of secondary winding, wherein A, B, C three-phase each to 8 power cells should be arranged;

A power electronics converter plant (PE), this converter plant adopts cascade connection type topological structure, whenever is made up of 8 power unit cascades, and star-like connection is exported; Power cell adopts three-phase not control the rectification input, electrochemical capacitor DC filtering, the 2H bridge output that insulation gate pole bipolar transistor IGBT is formed; Each power cell of power electronics converter plant inserts the alternating current of the three-phase rated line voltage 720V/50Hz of the corresponding secondary winding output of phase shift isolating transformer, in each power cell, set up independent direct voltage then through rectifying and wave-filtering, last each power cell is realized the conversion of direct current-high-frequency ac by pulse modulation technology, and the cascade by 8 power cells of every phase promptly can produce the specified 10KV/ of three-phase (1000～1800Hz) high-frequency alternating current;

A three-phase resonant capacitor heap (RC), its basic composition is the noninductive big current film capacitor of 100A/3000V, connection in series-parallel by them connects the withstand voltage and current carrying capacity that improves electric capacity, realizes the actual resonant capacitor heap under the high-voltage great-current operating condition

The input of high voltage high power resonant vibration frequency conversion deicing device is the phase shift isolating transformer, and the output of each winding of transformer secondary connects with corresponding power electronics converter plant power cell, every 8 cascade of power units connections in mutually, and output is A ', B ', C '; The three-phase input end of resonant capacitor heap is connected with A ', B ', C ' the three-phase output correspondence of power electronics converter plant respectively, and output A, B, the C of resonant capacitor heap directly are connected with the deicing circuit.

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