CN106329512A - According to the technical scheme provided by the present invention, the black-start speed and stability of the power grid are improved. - Google Patents

Abstract

The present invention provides a converter valve design method used for DC system black-start. The method comprises the steps of building a converter valve system simulation model; utilizing the converter valve system simulation model to obtain the voltage and the current stress in a converter valve and the loss of damping loops, a thyristor and a lightning arrester when a DC system is utilized to carry out the power grid black-start; configuring the parameters of the lightning arrester of the converter valve; utilizing the converter valve system simulation model and integrating the loss of different damping loops, the turn-on and turn-off loss of the thyristor and a converter valve phase commutation overshoot peak value to obtain an optimal scheme of the damping parameter configuration and the waterway configuration; analyzing the black-start operation capability of the converter valve, and determining whether the lightning arrester acts when the converter valve is at the power grid black-start by a leakage current waveform of the lightning arrester of the converter valve obtained by simulation; determining whether the converter valve can operate stably on the black-start condition by the loss of the lightning arrester. According to the technical scheme provided by the present invention, the black-start speed and stability of the power grid are improved.

Description

A kind of converter valve method for designing for straight-flow system black starting-up

Technical field

The present invention relates to converter valve method for designing, be specifically related to a kind of converter valve method for designing for straight-flow system black starting-up.

Background technology

In power grid"black-start" technical field, extensive from the selection of black starting-up power supply, the rule and policy in black starting-up stage, electrical network both at home and abroad The aspects such as multiple path optimization have carried out theoretical research for many years, and are successfully made a series of exchange based on achievement in research Power grid"black-start" is tested.And for straight-flow system is compared to the startup of AC system, have that conveying power is big, start and adjust speed The features such as degree is fast, controllability is strong, these features can play bigger effect at the black starting-up initial stage, it is possible to accelerates networking, strengthens power transmission Ability.But, in terms of utilizing straight-flow system to drive power grid"black-start", still it is in the starting stage, is also all based on converter It is desired operation, does not consider that converter is for ability to bear to voltage, electric current and loss during black starting-up.

Inverter is when power grid"black-start", and commutation will be caused to cross punching to be increased, and in converter valve, IGCT causes loss owing to frequently cut-offfing Increasing, spark gap shifts the series of problems such as energy increase.In view of the efficiency of water-cooling system, to the restriction being lost by relatively stringent, Thus the black start-up ability problem of direct-current transmission converter valve becomes the problem needing solution in an engineering badly.

Summary of the invention

For solving above-mentioned deficiency of the prior art, it is an object of the invention to provide a kind of converter valve for straight-flow system black starting-up Method for designing, improves black starting-up speed and the stability of electrical network.

It is an object of the invention to use following technical proposals to realize:

A kind of converter valve method for designing for straight-flow system black starting-up, it thes improvement is that, described method includes:

Build converter valve system simulation model: utilize converter valve system simulation model to be obtained by straight-flow system and carry out power grid"black-start" Time converter valve in the loss of voltage, current stress and damping circuit, IGCT and spark gap；

Configuration converter valve spark gap parameter: utilize described converter valve system simulation model, the most different damping circuit loss, brilliant Brake tube turns on and off loss, converter valve commutation overshoot voltage peak value, obtains damping parameter configuration and the optimal case of water route configuration；

Analyze converter valve black starting-up service ability, and the converter valve lightning arrester leakance waveform obtained by emulation judges that converter valve is at electricity During net black starting-up, spark gap whether action；Judged whether converter valve can stable operation in the case of black starting-up by spark gap loss.

Wherein, build converter valve system simulation model described in include:

Build 6 pulse conversion units: include converter power transformer, damping resistance, damping capacitor, direct current equalizing resistance, IGCT, Stray capacitance and valve arrester in valve reactor, valve；Converter power transformer passes through equivalent reactance device and the three phase rectifier of converter valve system Bridging connects；The each of three-phase commutation bridge is constituted by upper and lower two brachium pontis, and each brachium pontis is constituted by converter valve；Each converter valve Two ends parallel valve spark gap；Described converter valve includes that damping circuit, direct current all push back in road, IGCT, saturable reactor and valve Stray capacitance；Described damping circuit, direct current form damping circuit-direct current after all pushing back road and IGCT parallel connection and all push back road-crystalline substance lock Pipe parallel branch, damping circuit-direct current all pushes back road-IGCT parallel branch and connects with saturable reactor with stray capacitance in valve also Connection；

Parameter is inputted in the converter valve system simulation model established, including: IGCT on-state voltage drop U_T, IGCT slope electricity Resistance R_T, IGCT off-state resistance R_D, IGCT maintain electric current I_w, converter valve damping capacitor C_S, converter valve damping resistance R_S、 Direct current equalizing resistance R_dc, saturable reactor unsaturation inductance value L_mWith stray capacitance capacitance C_y。

Wherein, described configuration converter valve spark gap parameter includes:

U-I characteristic according to monolithic arrester valve piece and converter valve switching-surge protective level SIPL, calculate converter valve spark gap Required connection in series-parallel sheet number N_arr；

Calculate the converter valve spark gap U-I characteristic after connection in series-parallel；

Spark gap U-I parameter is inputted in converter valve system simulation model.

Wherein, described connection in series-parallel sheet number N_arrCalculate with following formula:

$N_{arr}=\frac{U_{SIWZ}}{U_{R\left(s\right)}}$

Wherein, U_SIWZFor converter valve switching impulse level of protection, U_R(s)For arrester valve piece residual voltage under specified running current Value.

Wherein, the U-I characteristic of the monolithic arrester valve piece that described converter valve spark gap U-I characteristic is provided by spark gap producer is multiplied by Valve block serial number obtains.

Wherein, described analysis converter valve black starting-up service ability includes:

Commutation overshoot voltage when emulation converter valve turns off；

Calculate leakage current of an arrester and loss；

Calculating damping circuit is lost；

Calculate the loss in the case of IGCT frequently cut-offs；

Calculate IGCT and run junction temperature.

Wherein, described spark gap Leakage Current i_aObtained by spark gap U-I characteristic；

Spark gap loss expressions below represents:

$P_a=50{\∫}_0^T{V}_a{i}_{a}dt;$

Wherein, V_aFor spark gap both end voltage, i_aFor spark gap Leakage Current；T is power frequency period, takes 0.02s.

Wherein, damping circuit loss is lost P by damping resistance_RSP is lost with damping capacitor_CSTwo parts are added and constitute:

$P_{RS}=2{\mathrm{\πf}}^2{U}_{V0}^2{C}_{AC}^2{R}_{AC}\{\frac{4\mathrm{\π}}{3}-\frac{\sqrt{3}}{2}-\frac{7\mathrm{\μ}}{4}+\frac{7}{8}sin2\mathrm{\α}+\frac{7}{8}sin(2\mathrm{\α}+2\mathrm{\μ})\}$

$P_{CS}=\frac{7U_{V0}^2\×f\×C_{HF}}{4}\[{\sin }^2\left(\mathrm{\α}\right)+{\sin }^2(\mathrm{\α}+\mathrm{\μ})\]$

Wherein: T is power frequency period, takes 0.02s；C_ACFor converter valve two ends effective damping capacitance；R_ACFor with C_ACSeries connection Effective damping resistance value；C_ACIt is that the design load of damping capacitor of a valve is divided by the IGCT number of this valve；R_ACIt it is the resistance of a valve The design load of buffer resistance is multiplied by the IGCT number of this valve；C_HFAll capacitive equalizing lattice effective total capacitances of network branch road for valve two ends； U_V0For valve side line voltage；F is system frequency；μ is angle of overlap；α is Trigger Angle.

Wherein, the loss expression formula in the case of IGCT frequently cut-offs is as follows:

$P=50{\∫}_0^T(V_{T0}+r_{T}i)idt$

Wherein: V_T0For IGCT on-state threshold voltage；r_TFor IGCT on-state slope resistance；I is fault current instantaneous value；T For power frequency period, take 0.02s.

Wherein, the expression formula of described IGCT operation junction temperature is as follows:

T_j1=T_c+P_thy×R_thjc

Wherein: T_j1For IGCT junction temperature (DEG C)；T_cFor the highest coolant temperature at the radiator inlet of least favorable IGCT；P_thy It is lost for maximum continuous overload IGCT；R_thjcThe thermal resistance of coolant at this is tied for IGCT.

The excellent effect that the technical scheme that the present invention provides has is:

1. obtain valve arrester, damping circuit voltage, current waveform by the method for electromagnetic transient simulation, and utilize a cycle The method of interior integration is calculated spark gap loss, damping circuit loss and thyristor switch loss during straight-flow system black starting-up, Directly perceived effective.

2. utilize and build the setting of converter valve system model parameter, can repeatedly change damping parameter, the most different dampings in short-term Return loss and commutation overshoot voltage peak value, can find damping parameter configuration and the optimal case of water route configuration the most quickly.

3. the valve arrester leakage current waveform obtained by emulation can judge intuitively, fast converter valve when black starting-up, spark gap is No frequent movement；Converter valve can be analyzed whether can stable operation in the case of black starting-up by spark gap loss.

Accompanying drawing explanation

Fig. 1 is the flow chart of the converter valve method for designing for straight-flow system black starting-up that the present invention provides；

Fig. 2 is the converter valve system simulation model figure that the present invention provides.

Detailed description of the invention

Below in conjunction with the accompanying drawings the detailed description of the invention of the present invention is described in further detail.

The following description and drawings illustrate specific embodiments of the present invention fully, to enable those skilled in the art to put into practice it ?.Other embodiments can include structure, logic, electric, process and other change.Embodiment only generation The change that table is possible.Unless explicitly requested, otherwise individually assembly and function are optional, and the order operated can change. The part of some embodiments and feature can be included in or replace part and the feature of other embodiments.The enforcement of the present invention The scope of scheme includes the gamut of claims, and all obtainable equivalent of claims.In this article, These embodiments of the present invention can be represented by " inventing " individually or generally with term, and this is only used to conveniently, and And if in fact disclose the invention more than, be not meant to automatically to limit this application and in the range of any single invention or send out Bright design.

The present invention provides a kind of converter valve method for designing being applicable to straight-flow system black starting-up, and its flow chart is as it is shown in figure 1, include:

Converter valve system model builds step: utilizes the method building converter valve system simulation model to be obtained by straight-flow system and carries out The loss of the voltage in converter valve, current stress and damping circuit, IGCT and spark gap during power grid"black-start".

Converter valve spark gap parameter configuration step: utilize the phantom put up, the most different damping circuit losses, brilliant lock Pipe turns on and off loss, converter valve commutation overshoot voltage peak value, finds damping parameter configuration and the optimal case of water route configuration.

Converter valve black starting-up service ability analytical procedure: the valve arrester leakage current waveform obtained by emulation can converter valve exist intuitively During power grid"black-start", spark gap whether action；It is lost by spark gap and i.e. can determine whether whether converter valve can be stablized in the case of black starting-up Run.

1) converter valve system simulation model is built, and converter valve system simulation model is as in figure 2 it is shown, include following sub-step:

1. 6 pulse conversion units are built: include converter power transformer, damping resistance, damping capacitor, direct current equalizing resistance, brilliant lock Stray capacitance and valve arrester in pipe, valve reactor, valve；Converter power transformer passes through equivalent reactance device and the three-phase of converter valve system Rectifier bridge connects；The each of three-phase commutation bridge is constituted by upper and lower two brachium pontis, and each brachium pontis is constituted by converter valve；Each change Stream valve two ends parallel valve spark gap；Described converter valve include damping circuit, direct current all push back road, IGCT, saturable reactor and Stray capacitance in valve；Described damping circuit, direct current all push back road and IGCT parallel connection after form damping circuit-direct current all push back road- IGCT parallel branch, damping circuit-direct current all pushes back road-IGCT parallel branch and connects with saturable reactor and stray electrical in valve Hold parallel connection；

2. input parameter in the converter valve system simulation model put up: IGCT on-state voltage drop U_T, IGCT slope resistance R_T, IGCT off-state resistance R_D, IGCT maintain electric current I_w, converter valve damping capacitor C_S, converter valve damping resistance R_S, straight Stream equalizing resistance R_dc, saturable reactor unsaturation inductance value L_m, stray capacitance capacitance C_f。

2) spark gap parameter configuration step, including following sub-step:

1. according to U-I characteristic and the converter valve switching-surge protective level SIPL of monolithic arrester valve piece, valve arrester is calculated Required connection in series-parallel sheet number N_arr；Described connection in series-parallel sheet number N_arrRepresent by following expression:

$N_{arr}=\frac{U_{SIWZ}}{U_{R\left(s\right)}}$

Wherein, U_SIWZFor converter valve switching impulse level of protection, U_R(s)For arrester valve piece residual voltage under specified running current Value.

2. the valve arrester U-I characteristic after connection in series-parallel is calculated；Described converter valve spark gap U-I characteristic is provided by spark gap producer The U-I characteristic of monolithic arrester valve piece is multiplied by valve block serial number and obtains.

3. in converter valve system model, input spark gap U-I parameter.

3) converter valve black starting-up service ability analytical procedure, including following sub-step:

1. the emulation of commutation overshoot voltage, calculating when converter valve turns off；

2. leakage current of an arrester and loss are calculated；Spark gap Leakage Current i_aObtained by spark gap U-I characteristic；

Spark gap loss expressions below represents:

$P_a=50{\∫}_0^T{V}_a{i}_{a}dt;$

Wherein, V_aFor spark gap both end voltage, i_aFor spark gap Leakage Current；T is power frequency period, takes 0.02s.

3. damping circuit loss is calculated；Damping circuit loss is lost P by damping resistance_RSP is lost with damping capacitor_CSTwo parts phase Add composition:

$P_{RS}=2{\mathrm{\πf}}^2{U}_{V0}^2{C}_{AC}^2{R}_{AC}\{\frac{4\mathrm{\π}}{3}-\frac{\sqrt{3}}{2}-\frac{7\mathrm{\μ}}{4}+\frac{7}{8}sin2\mathrm{\α}+\frac{7}{8}sin(2\mathrm{\α}+2\mathrm{\μ})\}$

$P_{CS}=\frac{7U_{V0}^2\×f\×C_{HF}}{4}\[{\sin }^2\left(\mathrm{\α}\right)+{\sin }^2(\mathrm{\α}+\mathrm{\μ})\]$

Wherein: T is power frequency period, takes 0.02s；C_ACFor converter valve two ends effective damping capacitance；R_ACFor with C_ACSeries connection Effective damping resistance value；C_ACIt is that the design load of damping capacitor of a valve is divided by the IGCT number of this valve；R_ACIt it is the resistance of a valve The design load of buffer resistance is multiplied by the IGCT number of this valve；C_HFAll capacitive equalizing lattice effective total capacitances of network branch road for valve two ends； U_V0For valve side line voltage；F is system frequency；μ is angle of overlap；α is Trigger Angle.

4. the loss in the case of IGCT frequently cut-offs is calculated；Loss expression formula in the case of IGCT frequently cut-offs is as follows:

$P=50{\∫}_0^T(V_{T0}+r_{T}i)idt$

Wherein: V_T0For IGCT on-state threshold voltage；r_TFor IGCT on-state slope resistance；I is fault current instantaneous value；T For power frequency period, take 0.02s.

5. calculate IGCT and run junction temperature；The expression formula that IGCT runs junction temperature is as follows:

T_j1=T_c+P_thy×R_thjc

Wherein: T_j1For IGCT junction temperature (DEG C)；T_cFor the highest coolant temperature at the radiator inlet of least favorable IGCT；P_thy It is lost for maximum continuous overload IGCT；R_thjcThe thermal resistance of coolant at this is tied for IGCT.

Utilize build the method for converter valve system simulation model be obtained by voltage that straight-flow system carries out during power grid"black-start" in valve, Current stress and damping circuit, IGCT, spark gap loss.The most different damping circuit, IGCT loss and commutations Rush voltage peak, the optimal case that damping parameter configures can be found.Appropriate design converter valve water-cooling system is lost by IGCT, And the valve arrester leakage current waveform obtained by emulation can intuitively converter valve when black starting-up runs, spark gap whether frequent movement； It is lost by spark gap and i.e. can determine whether whether converter valve can stable operation in the case of black starting-up.

Above example is only in order to illustrate that technical scheme is not intended to limit, although with reference to above-described embodiment to the present invention Be described in detail, those of ordinary skill in the field still the detailed description of the invention of the present invention can be modified or Person's equivalent, these are without departing from any amendment of spirit and scope of the invention or equivalent, all await the reply in application this Within bright claims.

Claims (10)

1. the converter valve method for designing for straight-flow system black starting-up, it is characterised in that described method includes:

Build converter valve system simulation model: utilize converter valve system simulation model to be obtained by straight-flow system and carry out power grid"black-start" Time converter valve in the loss of voltage, current stress and damping circuit, IGCT and spark gap；

Configuration converter valve spark gap parameter: utilize described converter valve system simulation model, the most different damping circuit loss, brilliant Brake tube turns on and off loss, converter valve commutation overshoot voltage peak value, obtains damping parameter configuration and the optimal case of water route configuration；

Analyze converter valve black starting-up service ability, and the converter valve lightning arrester leakance waveform obtained by emulation judges that converter valve is at electricity During net black starting-up, spark gap whether action；Judged whether converter valve can stable operation in the case of black starting-up by spark gap loss.

2. converter valve method for designing as claimed in claim 1, it is characterised in that described in build converter valve system simulation model bag Include:

Build 6 pulse conversion units: converter power transformer is connected with three-phase commutation bridge by the equivalent reactance device of converter valve system；Three The each of commutating phase bridge is constituted by upper and lower two brachium pontis, and each brachium pontis is constituted by converter valve；Each converter valve two ends parallel valve Spark gap；Described converter valve includes that damping circuit, direct current all push back stray capacitance in road, IGCT, saturable reactor and valve； Described damping circuit, direct current form damping circuit-direct current after all pushing back road and IGCT parallel connection and all push back road-IGCT parallel branch, Damping circuit-direct current all pushes back road-IGCT parallel branch and connects with saturable reactor in parallel with stray capacitance in valve；

Parameter is inputted in the converter valve system simulation model established, including: IGCT on-state voltage drop U_T, IGCT slope electricity Resistance R_T, IGCT off-state resistance R_D, IGCT maintain electric current I_w, converter valve damping capacitor C_S, converter valve damping resistance R_S、 Direct current equalizing resistance R_dc, saturable reactor unsaturation inductance value L_mWith stray capacitance capacitance C_y。

3. converter valve method for designing as claimed in claim 1, it is characterised in that described configuration converter valve spark gap parameter includes:

U-I characteristic according to monolithic arrester valve piece and converter valve switching-surge protective level SIPL, calculate converter valve spark gap Required connection in series-parallel sheet number N_arr；

Calculate the converter valve spark gap U-I characteristic after connection in series-parallel；

Spark gap U-I parameter is inputted in converter valve system simulation model.

4. converter valve method for designing as claimed in claim 3, it is characterised in that described connection in series-parallel sheet number N_arrCalculate with following formula:

$N_{arr}=\frac{U_{SIWZ}}{U_{R\left(s\right)}}$

Wherein, U_SIWZFor converter valve switching impulse level of protection, U_R(s)For arrester valve piece residual voltage under specified running current Value.

5. converter valve method for designing as claimed in claim 3, it is characterised in that described converter valve spark gap U-I characteristic is by keeping away The U-I characteristic of the monolithic arrester valve piece that Lei Qi producer provides is multiplied by valve block serial number and obtains.

6. converter valve method for designing as claimed in claim 1, it is characterised in that described analysis converter valve black starting-up service ability Including:

Commutation overshoot voltage when emulation converter valve turns off；

Calculate leakage current of an arrester and loss；

Calculating damping circuit is lost；

Calculate the loss in the case of IGCT frequently cut-offs；

Calculating IGCT and run junction temperature, its expression formula is as follows:

T_j1=T_c+P_thy×R_thjc

Wherein: T_j1: IGCT junction temperature (DEG C)；T_c: the highest coolant temperature at the radiator inlet of least favorable IGCT；P_thy: Maximum overload IGCT loss continuously；R_thjc: IGCT ties the thermal resistance of coolant at this.

7. converter valve method for designing as claimed in claim 6, it is characterised in that described spark gap Leakage Current i_aBy spark gap U-I characteristic obtains；

Spark gap loss expressions below represents:

$P_a=50{\∫}_0^T{V}_a{i}_{a}dt;$

Wherein, V_aFor spark gap both end voltage, i_aFor spark gap Leakage Current；T is power frequency period, takes 0.02s.

8. converter valve method for designing as claimed in claim 6, it is characterised in that damping circuit loss is lost by damping resistance P_RSP is lost with damping capacitor_CSTwo parts are added and constitute:

$\begin{array}{c}{P}_{RS}=2{\mathrm{\πf}}^2{U}_{V0}^2{C}_{AC}^2{R}_{AC}\{\frac{4\mathrm{\π}}{3}-\frac{\sqrt{3}}{2}-\frac{7\mathrm{\μ}}{4}+\frac{7}{8}sin2\mathrm{\α}+\frac{7}{8}sin(2\mathrm{\α}+2\mathrm{\μ})\}\\ P_{CS}=\frac{7U_{V0}^2\×f\×C_{HF}}{4}\[{\sin }^2\left(\mathrm{\α}\right)+{\sin }^2(\mathrm{\α}+\mathrm{\μ})\]\end{array}$

Wherein: T is power frequency period, takes 0.02s；C_ACFor converter valve two ends effective damping capacitance；R_ACFor with C_ACSeries connection Effective damping resistance value；C_ACIt is that the design load of damping capacitor of a valve is divided by the IGCT number of this valve；R_ACIt it is the resistance of a valve The design load of buffer resistance is multiplied by the IGCT number of this valve；C_HFAll capacitive equalizing lattice effective total capacitances of network branch road for valve two ends； U_V0For valve side line voltage；F is system frequency；μ is angle of overlap；α is Trigger Angle.

9. converter valve method for designing as claimed in claim 6, it is characterised in that IGCT frequently cut-off in the case of attrition table Reach formula as follows:

$P=50{\∫}_0^T(V_{T0}+r_{T}i)idt$

Wherein: V_T0For IGCT on-state threshold voltage；r_TFor IGCT on-state slope resistance；I is fault current instantaneous value；T For power frequency period, take 0.02s.

10. converter valve method for designing as claimed in claim 6, it is characterised in that described IGCT runs the expression formula of junction temperature As follows:

T_j1=T_c+P_thy×R_thjc

Wherein: T_j1For IGCT junction temperature (DEG C)；T_cFor the highest coolant temperature at the radiator inlet of least favorable IGCT；P_thy It is lost for maximum continuous overload IGCT；R_thjcThe thermal resistance of coolant at this is tied for IGCT.