CN106207863A - A kind of based on the THE UPFC de-icing method of synchronization paralleling device between electrical network - Google Patents

Abstract

The invention discloses a kind of based on the THE UPFC de-icing method of synchronization paralleling device between electrical network, there is after simultaneous interconnecting device is converted to THE UPFC the function of load disturbance, make icing circuit overload, load current increase by through-put power and realize ice-melt.Emulated by PSCAD/EMTDC, test result indicate that after carrying out certain power transmission, the load current on icing circuit can reach ice-melt effect, illustrate to be carried out by power transmission feasibility and the effectiveness of line ice-melting theoretically.Grid-connecting apparatus is changed into UPFC laggard row line ice-melt by the present invention, reaches same device and realizes the effect of several functions, improves utilization rate and the economic benefit of equipment.

Description

A kind of based on the THE UPFC de-icing method of synchronization paralleling device between electrical network

Technical field

The invention discloses a kind of based on the THE UPFC de-icing method of synchronization paralleling device between electrical network, belong to electricity Power electronic technology field.

Background technology

Transmission line of electricity icing in the winter time is a kind of natural disaster that power system is common.China is also that icing is the tightest in the world One of country of weight.Owing to wire adds ice load, wire, steel tower and gold utensil all can be brought certain mechanical failure, cover Can break when ice is serious, fall shaft tower, cause large area blackout.Solve icing problem, improve the reliability of power system also It it is the requirement place of intelligent grid.Present stage, the electric power research personnel of many countries are studying anti-icing and deicing measure, domestic The technology of outer ice-removing and ice-preventing up to kind more than 30, generally speaking can be divided into 4 classes, i.e. heating power deicing method, mechanical deicing's method, passively remove Ice method and other de-icing methods.Mechanical deicing's method power consumption is little, and low cost, but operating difficulties, safety is poor, passive ice-melt Method is inefficient, it is impossible to remove icing thoroughly.At present, main de-icing technology is exactly thermal ice-melting method.The base of thermal ice-melting Present principles is to pass on the line carry out ice-melt higher than the transmission electric current of normal current density to obtain Joule heat.Main heating power De-icing method has following several: overload ice-melt, ac short circuit ice-melt, direct current ice melting method.But these 3 kinds of methods all exist necessarily Defect: ac short circuit ice-melt and DC ice melting are required for circuit and disconnect with major network, if icing is basic routing line, will certainly be right The reliable and stable operation of electrical network brings greater impact.Ac short circuit ice-melt belongs to accident treatment in the character of operation, specifically real Execute operation task many and numerous and diverse.Overload ice-melt benefit is to need not disconnect circuit, but cannot regulate line exactly The power of transmission on road.

Summary of the invention

The technical problem to be solved is the deficiency for above-mentioned background technology, it is provided that between one is based on electrical network The THE UPFC interconnection de-icing method of synchronization paralleling device.The function of power transmission is carried out, in conjunction with heat for UPFC The principle of power ice-melt, utilizes UPFC to increase the power of transmission on icing circuit, and line loss increases with the purpose reaching ice-melt.

The present invention adopts the following technical scheme that for achieving the above object

A kind of based on the THE UPFC de-icing method of synchronization paralleling device between electrical network, comprise the steps:

(1) transmission system parameter is utilized to set up THE UPFC UPFC model；

(2) utilize software that UPFC model carries out simulation analysis, verify UPFC power flowcontrol ability；

(3) utilize UPFC to increase the power of transmission on icing circuit, make line loss increase, it is achieved ice-melt.

Aforesaid step (1), the transmission system parameter accessing UPFC device is:

Wherein,It is respectively circuit first Terminal voltage, line end voltage, UPFC series compensating voltage, line impedance, transmission system receiving end active power, transmission system are subject to End reactive power, UPFC inject meritorious, UPFC inject idle, first and last end supply voltage phase contrast, UPFC series compensating voltage with Head end supply voltage phase contrast.

UPFC model is emulated by aforesaid step (2) as follows:

(2-1) UPFC model, UPFC model emulation checking power flowcontrol energy are set up with the transmission system parameter of step (1) Power；

(2-2) UPFC device accesses transmission system, and two side systems are respectivelyWithLine impedance is X, UPFC series connection Compensate voltage phasorRepresent, withFor arbitrarily running in the disk of end points, transmission system receiving end do not put into UPFC and Put into the power after UPFC as follows,

The plural form of the transmission system receiving end power putting into UPFC is:

$P-{\mathrm{jQ}}_r=\stackrel{\·}{U_r}{\left(\frac{\stackrel{\·}{U_s}+\stackrel{\·}{U_c}-\stackrel{\·}{U_r}}{jX}\right)}^{*}=\stackrel{\·}{U_r}{\left(\frac{\stackrel{\·}{U_s}-\stackrel{\·}{U_r}}{jX}\right)}^{*}+\frac{\stackrel{\·}{U_r}\stackrel{\·}{U_c^{*}}}{-jX}$

When not putting into UPFC, the plural form of transmission system receiving end power is:

$P_0-{\mathrm{jQ}}_{0r}=\stackrel{\·}{U_r}{\left(\frac{\stackrel{\·}{U_s}-\stackrel{\·}{U_r}}{jX}\right)}^{*}$

P₀Transmission system receiving end active power, Q during for putting into without UPFC_0rDuring for putting into without UPFC, transmission system receiving end is idle Power；

(2-3) when of putting into UPFC, it is assumed that transmission system line head end voltage, transmission line of electricity terminal voltage, UPFC go here and there Connection compensates voltage and is respectively as follows:

$\stackrel{\·}{U_s}={\mathrm{Ue}}^{j\mathrm{\δ}/2}=U(cos\frac{\mathrm{\δ}}{2}+jsin\frac{\mathrm{\δ}}{2})$

$\stackrel{\·}{U_r}={\mathrm{Ue}}^{-j\mathrm{\δ}/2}=U(cos\frac{\mathrm{\δ}}{2}-jsin\frac{\mathrm{\δ}}{2})$

$\stackrel{\·}{U_c}=U_c{e}^{-j(\mathrm{\δ}/2+\mathrm{\ρ})}=U_c\left(cos\right(\frac{\mathrm{\δ}}{2}+\mathrm{\ρ})+jsin(\frac{\mathrm{\δ}}{2}+\mathrm{\ρ}\left)\right)$

Wherein: U is not install the circuit head end voltage of UPFC, the voltage magnitude of line end voltage, U_cFor series compensation The voltage magnitude of voltage；

(2-4) UPFC is filled with an amplitude and the adjustable voltage of phase angle to systemBy rightIt is adjusted The change of load disturbance, the phasor form of the transmission system receiving end power putting into UPFC device is:

$P_0+{\mathrm{jQ}}_{0r}=\frac{U^2}{X}sin\mathrm{\δ}+\frac{U^2}{X}(1-cos\mathrm{\δ})$

The phasor form of UPFC through-put power is:

$P_c-{\mathrm{jQ}}_c=\frac{{\mathrm{UU}}_c}{X}sin(\mathrm{\δ}+\mathrm{\ρ})+\frac{{\mathrm{UU}}_c}{X}cos(\mathrm{\δ}+\mathrm{\ρ}).$

Aforesaid step (2) utilizes software that UPFC model is carried out simulation analysis, it is impossible to show exactly melting of line ice coating Change, therefore the ice melting current value target as emulation can be reached after carrying out power transmission through UPFC using line current.

In aforesaid step (3), it is achieved ice-melt, needing to consider ice melting current and ice-melt time, relation between the two is such as Under:

$t=\frac{\[c_i(273.15-T_a)+L_F\]{\mathrm{\ρ}}_i{r}_i(2r_0-\frac{\mathrm{\π}}{2}{r}_i)}{I^2{R}_e}$

Wherein, t is the ice-melt time, c_iFor the specific heat capacity of ice, T_aFor temperature, L_FFor latent heat, ρ_iFor the density of ice, r_iFor Wire radius, R_eFor the resistance of unit length wire, I is ice melting current.

Carry out judging whether icing melts by installing icing on-Line Monitor Device.

The method have the advantages that

(1) between electrical network, synchronization paralleling device is converted to UPFC after grid-connected success, carries out power flowcontrol with UPFC, and increase is covered The power of transmission on ice circuit, can be to icing line ice-melting.

(2) present invention carries out ice-melt, it is not necessary to disconnects icing circuit, does not affect load operation.

(3) grid-connecting apparatus is changed into UPFC laggard row line ice-melt, reaches same device and realizes the effect of several functions, carries The utilization rate of high equipment and economic benefit.

Accompanying drawing explanation

Fig. 1 be the present invention based on the tool of the THE UPFC interconnection de-icing method of synchronization paralleling device between electrical network Body flow process.

Fig. 2 is UPFC circuit structure diagram.

Fig. 3 (a) is for accessing the power system equivalent circuit diagram of UPFC, and Fig. 3 (b) is the power system phasor accessing UPFC Figure.

Fig. 4 is the structure chart that UPFC device carries out ice-melt.

Fig. 5 is the change curve of transmitting active power on circuit AB.

Fig. 6 is the change curve of circuit AB every phase current virtual value.

Detailed description of the invention

The invention will be further described below in conjunction with the accompanying drawings.Following example are only used for clearly illustrating the present invention Technical scheme, and can not limit the scope of the invention with this.

The present invention is proposing between a kind of electrical network based on power transmission on the basis of the method for synchronization paralleling, by the method Combine with STATCOM (STATCOM) technology, form one and can realize synchronization paralleling between electrical network, again can be side by side After success, electrical network is carried out reactive-load compensation hybrid system.This system, before grid-connected, is transmitted by power, makes to treat coordinate system two The voltage of side, frequency, phase angle reach unanimity, and then carry out and net operation.After grid-connected success, by controlling the folding of chopper, Make grid-connecting apparatus be converted to STATCOM and electrical network is carried out reactive-load compensation.

This grid-connected system structurally with THE UPFC (unified power flow controller UPFC) there is certain similarity.And power system can be gained merit by UPFC, idle, voltage, impedance and merit angle etc. are entered respectively Row the most dynamically controls, the operation of beneficially optimization system, improves transient stability and the damping system vibration of system, improves line Road transmission capacity, has an enormous advantage relative to STATCOM.In order to reach the Appropriate application of resource, the function of expanding unit, Grid-connected system is converted to the UPFC utilization ratio with raising electrical equipment after grid-connected success, and then improves the transmission of electricity energy of system Power, alleviates and solves Congestion phenomenon, and economically decrease the cost of grid-connected system.

The basic structure of UPFC such as Fig. 2.By inverter 1 by transformator T1 and lines in parallel, inverter 2 passes through transformator T2 connects with circuit, is connected by bulk dc capacitor between 2 inverters.UPFC is as representative flexible AC transmission System (FACTS) equipment has been provided simultaneously with STATCOM and the advantage of SSSC (SSSC), highlights unified control The advantage of system, can be carried out comprehensively load end fundamental voltage, the reactive power of load, the active power of circuit and reactive power Regulation and control, can regulate size and the phase place of fundamental voltage effectively, can make the tide optimization of power system, improve stablizing of system Property, make transmission of electricity relatively reliable effectively.

The present invention based on the THE UPFC interconnection de-icing method of synchronization paralleling device between electrical network, such as Fig. 1 institute Show, comprise the steps:

Step 1, utilizes transmission system parameter to set up THE UPFC (UPFC) model.

The initial parameter of access UPFC device:Wherein,

It is respectively circuit head end voltage, line end voltage, UPFC series compensation Voltage, line impedance, transmission system receiving end active power, transmission system receiving end reactive power, UPFC inject meritorious, UPFC injection Idle, first and last end supply voltage phase contrast, UPFC series compensating voltage and head end supply voltage phase contrast；

Step 2, emulates UPFC model, verifies UPFC power flowcontrol ability；Emulate as follows:

Step 2-1, sets up UPFC Model, THE UPFC mould with the initial structure parameter of step 1 Type simulating, verifying power flowcontrol ability；

Step 2-2, UPFC device accesses transmission system, and shown in equivalent circuit diagram such as Fig. 3 (a), two side systems are respectively WithLine impedance is X, and line impedance produces pressure drop phasorRepresent, UPFC series compensating voltage phasorRepresent, It can withFor arbitrarily running in the disk of end points, P_cRepresent the active power that UPFC injects, transmission of electricity system to circuit head end Power calculation algorithms after system receiving end does not put into UPFC and puts into UPFC is as follows,

The plural form of the transmission system receiving end power putting into UPFC is:

$P-{\mathrm{jQ}}_r=\stackrel{\·}{U_r}{\left(\frac{\stackrel{\·}{U_s}+\stackrel{\·}{U_c}-\stackrel{\·}{U_r}}{jX}\right)}^{*}=\stackrel{\·}{U_r}{\left(\frac{\stackrel{\·}{U_s}-\stackrel{\·}{U_r}}{jX}\right)}^{*}+\frac{\stackrel{\·}{U_r}\stackrel{\·}{U_c^{*}}}{-jX}$

And when not putting into UPFC, the plural form of transmission system receiving end power is:

$P_0-{\mathrm{jQ}}_{0r}=\stackrel{\·}{U_r}{\left(\frac{\stackrel{\·}{U_s}-\stackrel{\·}{U_r}}{jX}\right)}^{*}$

P₀Transmission system receiving end active power, Q during for putting into without UPFC_0rDuring for putting into without UPFC, transmission system receiving end is idle Power.

Step 2-3, according to the phasor diagram of Fig. 3 (b), the when of putting into UPFC, it is assumed that transmission system line head end voltage, defeated Electric line terminal voltage, UPFC series compensating voltage are respectively as follows:

$\stackrel{\·}{U_s}={\mathrm{Ue}}^{j\mathrm{\δ}/2}=U(cos\frac{\mathrm{\δ}}{2}+jsin\frac{\mathrm{\δ}}{2})$

$\stackrel{\·}{U_r}={\mathrm{Ue}}^{-j\mathrm{\δ}/2}=U(cos\frac{\mathrm{\δ}}{2}-jsin\frac{\mathrm{\δ}}{2})$

$\stackrel{\·}{U_c}=U_c{e}^{-j(\mathrm{\δ}/2+\mathrm{\ρ})}=U_c\left(cos\right(\frac{\mathrm{\δ}}{2}+\mathrm{\ρ})+jsin(\frac{\mathrm{\δ}}{2}+\mathrm{\ρ}\left)\right)$

Wherein: U is not install the circuit head end voltage of UPFC, the voltage magnitude of line end voltage, U_cFor series compensation The voltage magnitude of voltage,

Step 2-4, UPFC is filled with an amplitude and the adjustable voltage of phase angle to systemBy rightIt is adjusted I.e. can be with the change of load disturbance.The phasor form of the transmission system receiving end power putting into UPFC device is:

$P_0+{\mathrm{jQ}}_{0r}=\frac{U^2}{X}sin\mathrm{\δ}+\frac{U^2}{X}(1-cos\mathrm{\δ})$

The phasor form of UPFC through-put power is:

$P_c-{\mathrm{jQ}}_c=\frac{{\mathrm{UU}}_c}{X}sin(\mathrm{\δ}+\mathrm{\ρ})+\frac{{\mathrm{UU}}_c}{X}cos(\mathrm{\δ}+\mathrm{\ρ}).$

Step 3, carries out the function of power transmission for UPFC, in conjunction with the principle of thermal ice-melting, utilizes UPFC to increase icing The power of transmission on circuit, line loss increases with the purpose reaching ice-melt.

In step 2, when using software that UPFC model is carried out simulation analysis, it is impossible to show exactly melting of line ice coating Change, therefore the ice melting current value target as emulation can be reached after carrying out power transmission through UPFC using line current.Carry out During great current deicing, it is overheated and damage that the effect in order to enable size of current to reach ice-melt is unlikely to again circuit, needs melting Ice electric current and ice-melt time calculate.Formula is as follows:

$t=\frac{\[c_i(273.15-T_a)+L_F\]{\mathrm{\ρ}}_i{r}_i(2r_0-\frac{\mathrm{\π}}{2}{r}_i)}{I^2{R}_e}$

Wherein: t is the ice-melt time, c_iFor the specific heat capacity of ice, T_aFor temperature, it is believed that ice-melt starts the temperature of ice on front wire Identical with temperature, L_FFor latent heat, ρ_iFor the density of ice, r_iFor wire radius, it is assumed that on line, icing is cylindrical shape ice, half Footpath is r₀, i.e. ice thickness is r₀-r_i, R_eFor the resistance of unit length wire, according to formula calculated above, can obtain at certain electricity Under stream I heating, melt the time required for different-thickness icing.

Obtaining ice melting current and ice-melt time data in particular situations according to test, the wire of 3 kinds of different models exists Minimum ice melting current result of the test when ambient temperature is-16 DEG C is as shown in table 1.Have wind and calm in the case of quick ice-melt time Between as shown in table 2.

The result of table 1 dissimilar wire minimum ice melting current test

Table 2 have wind and calm in the case of the quick ice-melt time

In emulation, for the consideration to electric pressure, select the data of LGJ300 model wire.Shown in table 1 is minimum Ice melting current, the time reaching ice-melt desirable effect can be the longest, table 2 show have wind and calm in the case of, ice melting current Size is essentially the same, differs bigger in time.Emulation being expected, the target ice melting current reached is set as 1100A.

Embodiment

Ice-melt illustraton of model according to Fig. 4 is built model at electromagnetic simulation software PSCAD/EMTDC and is emulated.Ac transmission Line voltage distribution grade is 220kV, a length of 30km of circuit AB, P_LFor the power of transmission, I on circuit AB_rmsFor each on circuit AB The virtual value of the electric current passed through on phase line.In simulations, by reference value P of adjusting circuit active power_refCircuit can be made The power of the upper transmission of AB changes.For avoiding system is caused greater impact, simultaneously can monitoring current virtual value in real time Change, uses at this UPFC to carry out power transmission slowly, regulates P in emulation_refIncrease 20MW every time.

Fig. 5, Fig. 6 are line transmission power and the simulation result of circuit monophase current virtual value.Can from two figures Going out, initial time, when UPFC is properly functioning, line transmission active power is about 210MW, and the virtual value of every phase current is about 0.55kA.About proceed by power flowcontrol during 5s, regulate P_refSlowly increasing, during the end of transmission, on circuit AB, transmission is meritorious Power is of about 420MW, and now every phase current virtual value also rises to about 1.20kA, has substantially met in ice-melt scheme and has set The requirement of 1100A ice melting current.

Using LGJ-300/40 wire, external diameter is 23.94mm, and resistance is 0.105 Ω/km.Assume that temperature is-17 DEG C, cover Ice is uniformly and thickness is 2cm.In ice-melt time formula, each parameter value is: c_i=2090J/kg DEG C, T_a=-17 DEG C, L_F= 335000J/kg, ρ_i=917kg/m³, r_i=0.01197m, r₀=0.03197m, R_e=0.105 Ω/km.Data according to emulation Taking I is that 1.2kA calculates, and the ice-melt time is 51min.In view of being continuously increased of line ice coating, the effect of wind-force and cover The factor frozen once again after ice-out, the actually required ice-melt time can be some larger, is referred in watch 2 test the fast of gained The speed ice-melt time, it is also possible to carry out judging whether icing melts by installing icing on-Line Monitor Device.If in practice When using this device to carry out line ice-melting, needing to take the action situation of relay protection into account, reasonable arrangement ice-melt operates.

The above is only the preferred embodiment of the present invention, it is noted that for the ordinary skill people of the art For Yuan, on the premise of without departing from the technology of the present invention principle, it is also possible to make some improvement and deformation, these improve and deformation Also should be regarded as protection scope of the present invention.

Claims (6)

1. one kind based on the THE UPFC de-icing method of synchronization paralleling device between electrical network, it is characterised in that include as follows Step:

(1) transmission system parameter is utilized to set up THE UPFC UPFC model；

(2) utilize software that UPFC model carries out simulation analysis, verify UPFC power flowcontrol ability；

(3) utilize UPFC to increase the power of transmission on icing circuit, make line loss increase, it is achieved ice-melt.

It is the most according to claim 1 a kind of based on the THE UPFC de-icing method of synchronization paralleling device between electrical network, It is characterized in that, described step (1), the transmission system parameter accessing UPFC device is:

Wherein,It is respectively circuit head end electricity Pressure, line end voltage, UPFC series compensating voltage, line impedance, transmission system receiving end active power, transmission system receiving end without Merit power, UPFC inject meritorious, UPFC injection idle, first and last end supply voltage phase contrast, UPFC series compensating voltage and head end Supply voltage phase contrast.

It is the most according to claim 2 a kind of based on the THE UPFC de-icing method of synchronization paralleling device between electrical network, It is characterized in that, UPFC model is emulated by described step (2) as follows:

(2-1) UPFC model, UPFC model emulation checking power flowcontrol ability are set up with the transmission system parameter of step (1)；

(2-2) UPFC device accesses transmission system, and two side systems are respectivelyWithLine impedance is X, UPFC series compensation electricity Pressure phasorRepresent, withFor arbitrarily running in the disk of end points, transmission system receiving end does not put into UPFC and input Power after UPFC is as follows,

The plural form of the transmission system receiving end power putting into UPFC is:

$P-{\mathrm{jQ}}_r=\stackrel{\·}{U_r}{\left(\frac{\stackrel{\·}{U_s}+\stackrel{\·}{U_c}-\stackrel{\·}{U_r}}{jX}\right)}^{*}=\stackrel{\·}{U_r}{\left(\frac{\stackrel{\·}{U_s}-\stackrel{\·}{U_r}}{jX}\right)}^{*}+\frac{\stackrel{\·}{U_r}\stackrel{\·}{U_c^{*}}}{-jX}$

When not putting into UPFC, the plural form of transmission system receiving end power is:

$P_0-{\mathrm{jQ}}_{0r}=\stackrel{\·}{U_r}{\left(\frac{\stackrel{\·}{U_s}-\stackrel{\·}{U_r}}{jX}\right)}^{*}$

P₀Transmission system receiving end active power, Q during for putting into without UPFC_0rTransmission system receiving end idle merit during for putting into without UPFC Rate；

(2-3) when of putting into UPFC, it is assumed that transmission system line head end voltage, transmission line of electricity terminal voltage, UPFC connect benefit Repay voltage to be respectively as follows:

$\stackrel{\·}{U_s}={\mathrm{Ue}}^{j\mathrm{\δ}/2}=U(cos\frac{\mathrm{\δ}}{2}+jsin\frac{\mathrm{\δ}}{2})$

$\stackrel{\·}{U_r}={\mathrm{Ue}}^{-j\mathrm{\δ}/2}=U(cos\frac{\mathrm{\δ}}{2}-jsin\frac{\mathrm{\δ}}{2})$

$\stackrel{\·}{U_c}=U_c{e}^{-j(\mathrm{\δ}/2+\mathrm{\ρ})}=U_c\left(cos\right(\frac{\mathrm{\δ}}{2}+\mathrm{\ρ})+j\sin (\frac{\mathrm{\δ}}{2}+\mathrm{\ρ}\left)\right)$

Wherein: U is not install the circuit head end voltage of UPFC, the voltage magnitude of line end voltage, U_cFor series compensating voltage Voltage magnitude；

(2-4) UPFC is filled with an amplitude and the adjustable voltage of phase angle to systemBy rightIt is adjusted controlling The change of trend, the phasor form of the transmission system receiving end power putting into UPFC device is:

$P_0+{\mathrm{jQ}}_{0r}=\frac{U^2}{X}sin\mathrm{\δ}+\frac{U^2}{X}(1-cos\mathrm{\δ})$

The phasor form of UPFC through-put power is:

$P_c-{\mathrm{jQ}}_c=\frac{{\mathrm{UU}}_c}{X}sin(\mathrm{\δ}+\mathrm{\ρ})+\frac{{\mathrm{UU}}_c}{X}cos(\mathrm{\δ}+\mathrm{\ρ}).$

It is the most according to claim 1 a kind of based on the THE UPFC de-icing method of synchronization paralleling device between electrical network, It is characterized in that, described step (2) utilizes software that UPFC model is carried out simulation analysis, it is impossible to show exactly melting of line ice coating Change, therefore the ice melting current value target as emulation can be reached after carrying out power transmission through UPFC using line current.

It is the most according to claim 1 a kind of based on the THE UPFC de-icing method of synchronization paralleling device between electrical network, It is characterized in that, in described step (3), it is achieved ice-melt, needing to consider ice melting current and ice-melt time, relation between the two is such as Under:

$t=\frac{\[c_i(273.15-T_a)+L_F\]{\mathrm{\ρ}}_i{r}_i(2r_0-\frac{\mathrm{\π}}{2}{r}_i)}{I^2{R}_e}$

Wherein, t is the ice-melt time, c_iFor the specific heat capacity of ice, T_aFor temperature, L_FFor latent heat, ρ_iFor the density of ice, r_iFor wire Radius, R_eFor the resistance of unit length wire, I is ice melting current.

It is the most according to claim 1 a kind of based on the THE UPFC de-icing method of synchronization paralleling device between electrical network, It is characterized in that, carry out judging whether icing melts by installing icing on-Line Monitor Device.