CN103605022B - A kind of converter valve damping element added losses defining method - Google Patents

Abstract

The present invention relates to the defining method of power electronics and field of power, be specifically related to a kind of converter valve damping element added losses defining method, comprise the steps: that the maximum line voltage value of converter power transformer is input in realistic model by (1); (2) damping parameter is input in realistic model; (3) computing module of damping element total losses is built; (4) realistic model Trigger Angle is adjusted to 15 °, Dynamic simulation model, draws the minimum added losses of damping element under accidental conditions; (5) realistic model Trigger Angle is adjusted to 90 °, Dynamic simulation model, draws the maximum added losses of damping element under the most severe operating condition; (6) final damping element added losses are drawn, converter valve realistic model is built according to converter valve real work circuit, realistic model can simulate the different Trigger Angle operating condition of converter valve, and determine converter valve damping element total losses under different Trigger Angle by emulation, computation process is simple and easy to do.

Description

A kind of converter valve damping element added losses defining method

Technical field

The present invention relates to the defining method of power electronics and field of power, be specifically related to a kind of converter valve damping element added losses defining method.

Background technology

Also there is no similar technological invention both at home and abroad at present.Usually, the loss of HVDC converter valve damping element calculates according to recommended formula, and computation process is more loaded down with trivial details, and deviation between result of calculation and active loss is larger.

Summary of the invention

For the deficiencies in the prior art, the object of this invention is to provide a kind of converter valve damping element added losses defining method, this method solve the computational problem of converter valve thyristor damping element added losses, converter valve realistic model is built according to converter valve real work circuit, realistic model can simulate the different Trigger Angle operating condition of converter valve, determine converter valve damping element total losses under different Trigger Angle by emulation, computation process is simple and easy to do.

The object of the invention is to adopt following technical proposals to realize:

The invention provides a kind of converter valve damping element added losses defining method, its improvements are, described method comprises the steps:

(1) the maximum line voltage value of converter power transformer is input in realistic model;

(2) damping parameter is input in realistic model;

(3) computing module of damping element total losses is built;

(4) realistic model Trigger Angle is adjusted to 15 °, Dynamic simulation model, draws the minimum added losses of damping element under accidental conditions;

(5) realistic model Trigger Angle is adjusted to 90 °, Dynamic simulation model, draws the maximum added losses of damping element under the most severe operating condition;

(6) final damping element added losses are drawn.

Further, in described step (1), build the realistic model of converter valve real work circuit, comprise the AC system, converter power transformer, bridge convertor circuit and the smoothing reactor that connect successively; Described smoothing reactor is connected with DC line;

Described AC system is made up of three-phase alternating-current supply, and described converter power transformer is the three-phase transformer of star-like connection;

Described bridge convertor circuit is three-phase bridge converter circuit, and form 6 pulsation rectifier bridges by 6 converter valve, two 6 pulse conversion circuit connected in series form 12 pulse conversion circuit; Described 12 pulse conversion circuit are by converter power transformer incoming transport system; Each converter valve two ends are parallel with lightning arrester.

Further, each 6 pulse conversion devices are with 6 thyrister bridge arm composition full-bridge rectification formula circuit; Be parallel with RC damping circuit at the thyristor two ends of converter valve, described RC damping circuit is by resistance R _dvwith electric capacity C _dvbe composed in series; Saturable reactor is connected with RC damping circuit.

Further, in described step (2), damping parameter comprises damping resistance instantaneous voltage U _in, current instantaneous value I _inwith a power frequency period T, by damping resistance instantaneous voltage U _in, current instantaneous value I _inbe input in the computing module of realistic model with a power frequency period T.

Further, in described step (3), build the computing module of damping element total losses, damping element total losses comprise damping element power total losses and damping element voltage jump total losses;

Calculate damping circuit power total losses according to damping parameter, the following formula of its principle of work describes:

$P_{\mathrm{total}}=\frac{1}{T}\×{\∫}_0^T{U}_{\mathrm{in}}{I}_{\mathrm{in}}\mathrm{dt}$ ①；

Damping element voltage jump total losses P _{rC-Δ U}represent with following formula:

$P_{\mathrm{RC}-\mathrm{\ΔU}}={\mathrm{\Σ}}_1^8\frac{C_{\mathrm{RC}}{\mathrm{\ΔU}}_n}{2T}$ ②；

Wherein: Δ U _nfor converter valve voltage jump amplitude within a work period; C _rCrepresent the capacitance of electric capacity in damping circuit.

Further, in described step (4), Dynamic simulation model, under drawing accidental conditions, the minimum added losses of damping element comprise the steps:

<1> determines the minimum value P of damping element total losses _total-min, Trigger Angle is adjusted to 15 °, draws now U _inand I _invalue, damping element power total losses minimum value is:

$P_{\mathrm{total}-\min }=\frac{1}{T}\&times;{\&Integral;}_0^T{U}_{\mathrm{in}}{I}_{\mathrm{in}}\mathrm{dt}$ ③；

<2> determines damping element voltage jump total losses minimum value P _{rC-Δ Umin}, Trigger Angle is adjusted to 15 °, damping element voltage jump total losses minimum value P _{rC-Δ Umin}for:

$P_{\mathrm{RC}-\mathrm{\&Delta;}U\min }={\mathrm{\&Sigma;}}_1^8\frac{C_{\mathrm{RC}}{\mathrm{\&Delta;U}}_n}{2T}$ ④；

<3> added losses minimum value P _add-min=P _total-min-P _{rC-Δ Umin}.

Further, in described step (5), Dynamic simulation model, under drawing the most severe operating condition, the maximum added losses of damping element comprise the steps:

A, determine the maximal value P of damping element total losses _total-max; Trigger Angle is adjusted to 90 ° and draws now U _inand I _invalue, damping element total losses maximal value is:

$P_{\mathrm{total}-\max }=\frac{1}{T}\&times;{\&Integral;}_0^T{U}_{\mathrm{in}}{I}_{\mathrm{in}}\mathrm{dt}$ ⑤；

B, determine damping element voltage jump total losses maximal value P _{rC-Δ Umax}; Trigger Angle is adjusted to 90 °, damping element voltage jump total losses maximal value P _{rC-Δ Umax}for:

$P_{\mathrm{RC}-\mathrm{\&Delta;}U\max }={\mathrm{\&Sigma;}}_1^8\frac{C_{\mathrm{RC}}{\mathrm{\&Delta;U}}_n^2}{2T}$ ⑥；

C, added losses maximal value P _add-max=P _total-max-P _{rC-Δ Umax}.

Further, in described step (6), final damping element added losses between added losses minimum value and added losses maximal value, that is:

P _add-min≤P _add≤P _add-max⑦。

Compared with the prior art, the beneficial effect that the present invention reaches is:

1, the present invention builds realistic model according to the real work circuit of converter valve, and determine converter valve damping element total losses under different Trigger Angle by emulation, computation process is simple and easy to do;

2, the present invention turn on and off according to converter valve and other valve turns on and off time valve both end voltage generation transition process in the damping circuit electric discharge at valve two ends and charging principle, derive the computing formula of damping element voltage jump loss, computing formula is applicable to damping element voltage jump loss calculation under all operating conditions;

3, computing method of the present invention can calculate damping element easily and to be in operation issuable added losses under all operating conditions, convenient and swift, save cost.

Accompanying drawing explanation

Fig. 1 is that the real work circuit of converter valve provided by the invention builds realistic model figure;

Fig. 2 is the process flow diagram of converter valve damping element added losses defining method provided by the invention.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.

In order to solve the computational problem of converter valve thyristor damping element added losses, the invention provides a kind of novel converter valve damping element added losses defining method.Build converter valve realistic model according to converter valve real work circuit, realistic model can simulate the different Trigger Angle operating condition of converter valve; The damping circuit in parallel at converter valve thyristor two ends, when converter valve both end voltage changes, damping circuit there will be charge and discharge process, with the discharge and recharge of damping circuit, damping resistance can produce loss.

The process flow diagram of converter valve damping element added losses defining method provided by the invention as shown in Figure 2, comprises the steps:

(1) by the realistic model of the maximum line voltage value of converter power transformer input converter valve real work circuit, as shown in Figure 1, converter valve real work circuit comprises the AC system, converter power transformer, bridge convertor circuit and the smoothing reactor that connect successively to its structural drawing; Described smoothing reactor is connected with DC line; Described AC system is made up of three-phase alternating-current supply, and described converter power transformer is the three-phase transformer of star-like connection; 6 converter valve composition 6 pulsation three-phase bridge converter circuits, two 6 pulse conversion circuit connected in series can form 12 pulse conversion circuit; Thyristor is the core switching device of converter valve; In order to limit current rise rate in thyristor opening process, in converter valve, is also furnished with saturable reactor; In order to prevent converter valve from bearing superpotential, converter valve two ends are parallel with lightning arrester; The commutation overshoot voltage occurred to suppress converter valve two ends, converter valve thyristor two ends are parallel with RC damping circuit, and described RC damping circuit is made up of resistance and electric capacity, are equivalent to the cascaded structure of a resistance and an electric capacity; According to the device that converter valve real work circuit and converter valve itself comprise, build converter valve realistic model.

(2) damping parameter being comprised damping resistance instantaneous voltage is U _in, current instantaneous value is I _inbe that T is input in the computing module of realistic model with a power frequency period;

(3) computing module of damping element total losses is built:

Build the computing module of damping element total losses, damping element total losses comprise damping element power total losses and damping element voltage jump total losses;

Calculate damping circuit power total losses according to damping parameter, the following formula of its principle of work describes:

$P_{\mathrm{total}}=\frac{1}{T}\&times;{\&Integral;}_0^T{U}_{\mathrm{in}}{I}_{\mathrm{in}}\mathrm{dt}$ ①；

Damping element voltage jump total losses P _{rC-Δ U}represent with following formula:

$P_{\mathrm{RC}-\mathrm{\&Delta;U}}={\mathrm{\&Sigma;}}_1^8\frac{C_{\mathrm{RC}}{\mathrm{\&Delta;U}}_n}{2T}$ ②；

Wherein: Δ U _nfor converter valve voltage jump amplitude within a work period; C _rCrepresent the capacitance of electric capacity in damping circuit.

(4) realistic model Trigger Angle is adjusted to 15 °, Dynamic simulation model, draws the minimum added losses of damping element under accidental conditions, comprise the steps:

<1> determines the minimum value P of damping element total losses _total-min, Trigger Angle is adjusted to 15 °, draws now U _inand I _invalue, damping element power total losses minimum value is:

$P_{\mathrm{total}-\min }=\frac{1}{T}\&times;{\&Integral;}_0^T{U}_{\mathrm{in}}{I}_{\mathrm{in}}\mathrm{dt}$ ③；

<2> determines damping element voltage jump total losses minimum value P _{rC-Δ Umin}, Trigger Angle is adjusted to 15 °, damping element voltage jump total losses minimum value P _{rC-Δ Umin}for:

$P_{\mathrm{RC}-\mathrm{\&Delta;}U\min }={\mathrm{\&Sigma;}}_1^8\frac{C_{\mathrm{RC}}{\mathrm{\&Delta;U}}_n}{2T}$ ④；

<3> added losses minimum value P _add-min=P _total-min-P _{rC-Δ Umin}.

(5) realistic model Trigger Angle is adjusted to 90 °, Dynamic simulation model, draws the maximum added losses of damping element under the most severe operating condition, comprise the steps:

A, determine the maximal value P of damping element total losses _total-max; Trigger Angle is adjusted to 90 ° and draws now U _inand I _invalue, damping element total losses maximal value is:

$P_{\mathrm{total}-\max }=\frac{1}{T}\&times;{\&Integral;}_0^T{U}_{\mathrm{in}}{I}_{\mathrm{in}}\mathrm{dt}$ ⑤；

B, determine damping element voltage jump total losses maximal value P _{rC-Δ Umax}; Trigger Angle is adjusted to 90 °, damping element voltage jump total losses maximal value P _{rC-Δ Umax}for:

$P_{\mathrm{RC}-\mathrm{\&Delta;}U\max }={\mathrm{\&Sigma;}}_1^8\frac{C_{\mathrm{RC}}{\mathrm{\&Delta;U}}_n^2}{2T}$ ⑥；

C, added losses maximal value P _add-max=P _total-max-P _{rC-Δ Umax}.

(6) final damping element added losses are drawn: finally damping element added losses are between added losses minimum value and added losses maximal value, that is:

P _add-min≤P _add≤P _add-max⑦。

Converter valve damping element added losses defining method provided by the invention, builds converter valve realistic model according to converter valve real work circuit, and realistic model can simulate the different Trigger Angle operating condition of converter valve; Calculate damping element to be easily in operation issuable added losses under all operating conditions.

Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit, although with reference to above-described embodiment to invention has been detailed description, those of ordinary skill in the field are to be understood that: still can modify to the specific embodiment of the present invention or equivalent replacement, and not departing from any amendment of spirit and scope of the invention or equivalent replacement, it all should be encompassed in the middle of right of the present invention.

Claims (6)

1. a converter valve damping element added losses defining method, is characterized in that, described method comprises the steps:

(1) the maximum line voltage value of converter power transformer is input in realistic model;

(2) damping parameter is input in realistic model;

(3) computing module of damping element total losses is built;

(4) realistic model Trigger Angle is adjusted to 15 °, Dynamic simulation model, draws the minimum added losses of damping element under accidental conditions;

(5) realistic model Trigger Angle is adjusted to 90 °, Dynamic simulation model, draws the maximum added losses of damping element under the most severe operating condition;

(6) final damping element added losses are drawn;

In described step (1), build the realistic model of converter valve real work circuit, comprise the AC system, converter power transformer, bridge convertor circuit and the smoothing reactor that connect successively; Described smoothing reactor is connected with DC line;

Described AC system is made up of three-phase alternating-current supply, and described converter power transformer is the three-phase transformer of star-like connection;

Described bridge convertor circuit is three-phase bridge converter circuit, forms 6 pulsation rectifier bridges by 6 converter valve, and two 6 pulsation rectifier bridges are composed in series 12 pulsation rectifier bridges; Described 12 pulsation rectifier bridges are by converter power transformer incoming transport system; Each converter valve two ends are parallel with lightning arrester;

Each 6 pulse conversion valves are made up of 6 thyrister bridge arms, and described 6 thyrister bridge arms form full-bridge rectification formula circuit; Be parallel with RC damping circuit at the thyristor two ends of converter valve, described RC damping circuit is by resistance R _dvwith electric capacity C _dvbe composed in series; Saturable reactor is connected with RC damping circuit.

2. damping element added losses defining method as claimed in claim 1, it is characterized in that, in described step (2), damping parameter comprises damping resistance instantaneous voltage U _in, current instantaneous value I _inwith a power frequency period T, by damping resistance instantaneous voltage U _in, current instantaneous value I _inbe input in the computing module of realistic model with a power frequency period T.

3. damping element added losses defining method as claimed in claim 1, it is characterized in that, in described step (3), build the computing module of damping element total losses, damping element total losses comprise damping element power total losses and damping element voltage jump total losses;

Calculate damping circuit power total losses according to damping parameter, the following formula of its principle of work describes:

$P_{total}=\frac{1}{T}\&times;{\&Integral;}_0^T{U}_{in}{I}_{in}dt$ ①；

Damping element voltage jump total losses P _{rC-Δ U}represent with following formula:

$P_{RC-\mathrm{\&Delta;}U}={\mathrm{\&Sigma;}}_1^8\frac{C_{RC}{\mathrm{\&Delta;U}}_n}{2T}$ ②；

Wherein: Δ U _nfor converter valve voltage jump amplitude within a work period; C _rCrepresent the capacitance of electric capacity in damping circuit;

U _infor damping resistance instantaneous voltage, I _infor current instantaneous value, T are a power frequency period.

4. damping element added losses defining method as claimed in claim 1, it is characterized in that, in described step (4), Dynamic simulation model, under drawing accidental conditions, the minimum added losses of damping element comprise the steps:

<1> determines the minimum value P of damping element total losses _total-min, Trigger Angle is adjusted to 15 °, draws now U _inand I _invalue, damping element power total losses minimum value is:

$P_{total-min}=\frac{1}{T}\&times;{\&Integral;}_0^T{U}_{in}{I}_{in}dt$ ③；

<2> determines damping element voltage jump total losses minimum value P _{rC-Δ Umin}, Trigger Angle is adjusted to 15 °, damping element voltage jump total losses minimum value P _{rC-Δ Umin}for:

$P_{RC-\mathrm{\&Delta;}Umin}={\mathrm{\&Sigma;}}_1^8\frac{C_{RC}{\mathrm{\&Delta;U}}_n}{2T}$ ④；

<3> added losses minimum value P _add-min=P _total-min-P _{rC-Δ Umin};

Wherein: U _infor damping resistance instantaneous voltage; I _infor current instantaneous value; T is a power frequency period; Δ U _nfor converter valve voltage jump amplitude within a work period; C _rCrepresent the capacitance of electric capacity in damping circuit.

5. damping element added losses defining method as claimed in claim 1, it is characterized in that, in described step (5), Dynamic simulation model, under drawing the most severe operating condition, the maximum added losses of damping element comprise the steps:

A, determine the maximal value P of damping element total losses _total-max; Trigger Angle is adjusted to 90 ° and draws now U _inand I _invalue, damping element total losses maximal value is:

$P_{total-max}=\frac{1}{T}\&times;{\&Integral;}_0^T{U}_{in}{I}_{in}dt$ ⑤；

B, determine damping element voltage jump total losses maximal value P _{rC-Δ Umax}; Trigger Angle is adjusted to 90 °, damping element voltage jump total losses maximal value P _{rC-Δ Umax}for:

$P_{RC-\mathrm{\&Delta;}Umax}={\mathrm{\&Sigma;}}_1^8\frac{C_{RC}{\mathrm{\&Delta;U}}_n^2}{2T}$ ⑥；

C, added losses maximal value P _add-max=P _total-max-P _{rC-Δ Umax};

Wherein: U _infor damping resistance instantaneous voltage, I _infor current instantaneous value, T are a power frequency period; Δ U _nfor converter valve voltage jump amplitude within a work period; C _rCrepresent the capacitance of electric capacity in damping circuit.

6. damping element added losses defining method as claimed in claim 5, is characterized in that, in step (6), final damping element added losses between added losses minimum value and added losses maximal value, that is:

P _add-min≤P _add≤P _add-max⑦；

Wherein: P _add-minfor added losses minimum value, P _add-maxfor added losses maximal value.