CN103605871B - A kind of Bulk power system simulation based on direct-current external characteristic matching analyzes method - Google Patents

Abstract

The invention belongs to field of power, be specifically related to a kind of Bulk power system simulation based on direct-current external characteristic matching and analyze method.The present invention sets up equivalent mini system in direct current near region to be studied, and builds its electrical-magnetic model；Obtain dc power external characteristic curve for fault to be studied by electromagnetic transient simulation, and be fitted with staircase curve；Multiple cutting load operation simulations in bulk power grid, and under same fault, carry out simulation analysis.The present invention can operate with in the theoretical research of power system, simulation analysis and operation control, the direct-current external characteristic curve provided by electromagnetic transient simulation organically combines with bulk power grid electromechanical transient simulation, effectively the bulk power grid containing straight-flow system can be carried out simulation analysis, solve direct current machine-electricity transient model and be difficult to a difficult problem for accurate simulation direct current dynamic response characteristic, be beneficial to systematic analysis, operations staff grasps the bulk power grid operation characteristic containing straight-flow system, improves power network safety operation level.

Description

A kind of Bulk power system simulation based on direct-current external characteristic matching analyzes method

Technical field

The invention belongs to field of power, be specifically related to a kind of Bulk power system simulation based on direct-current external characteristic matching and analyze method.

Background technology

Power adjustments is flexible, two end systems need not synchronize, transmission distance remote, transmission capacity owing to having for high voltage dc transmission technology The advantage such as big, is more and more applied in China's electrical network.Bulk power grid containing direct current is carried out effective simulation analysis, becomes It it is an important process.

Direct current is owing to containing a large amount of power electronic devices, needing to use electrical-magnetic model that it is carried out accurate modeling and simulating.Enter During row electromagnetic transient simulation, by calculating size limit, need bulk power grid is carried out Equivalent Simplification, reduce the accurate of computational analysis Property.Another kind of method is to set up the electromechanical transient approximate model of direct current, and the whole network is carried out electromechanical transient simulation.This method is not Foot is that the response characteristic of direct current is bigger with realistic model difference under some operating mode.Use electro-magnetic transient electromechanical transient hybrid simulation, Both it is contemplated that fast transient process within direct current, it is not required to again bulk power grid is carried out equivalence, accuracy of simulation can be effectively improved.But Industrial quarters lacks practical electro-magnetic transient-electromechanical transient hybrid simulation program at present.At bulk power grid based on direct-current external characteristic matching Simulating analysis aspect, there is not yet relevant report the most both at home and abroad.

Summary of the invention

For the deficiencies in the prior art, it is an object of the invention to provide a kind of Bulk power system simulation analysis based on direct-current external characteristic matching Method, the method for the present invention effectively can carry out simulation analysis to the bulk power grid containing straight-flow system, solve direct current machine-electricity transient model Being difficult to a difficult problem for accurate simulation direct current dynamic response characteristic, beneficially systematic analysis, operations staff grasp the bulk power grid containing straight-flow system Operation characteristic, improves power network safety operation level.

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

The present invention provides a kind of Bulk power system simulation based on direct-current external characteristic matching to analyze method, and it thes improvement is that, described side Method comprises the steps:

Step A: in bulk power grid machine-electricity transient model, retains direct current near region to be studied system, wears electrical network remainder Dimension south is equivalent, sets up equivalent mini system；

Step B: build the electrical-magnetic model of equivalent mini system, direct current to be studied uses detailed Controlling model；

Step C: for fault to be studied, equivalent mini system is carried out electromagnetic transient simulation, obtains outside the power of direct current to be studied Characteristic curve；

Step D: amendment bulk power grid machine-electricity transient model, replaces DC Model to be studied with constant power load model model, adjusts big electricity Network operation mode so that it is consistent with the equivalent mini system in electromagnetic transient simulation；

Step E: the power external characteristic curve treating researching DC carries out little step-length sampling, uses staircase curve matching；

Step F: be respectively provided with a cutting load operation for each ladder of matched curve, with step C same fault under to greatly Electrical network carries out electromechanical transient simulation analysis.

Further, in described step A, in bulk power grid machine-electricity transient model, centered by the change of current bus of direct current to be studied, Retaining the multistage outlet near region, at the bus of border, the electrical network remainder locating multistage outlet is carried out Thevenin's equivalence, foundation comprises Direct current near region system and the equivalent mini system of Thevenin's equivalence power supply.

Further, in described step B, build the electrical-magnetic model of equivalent mini system；Wherein, in electrical-magnetic model Circuit, electromotor, transformator, secondary capacitor and low tension reactor alternating current equipment use actual measurement parameter, if without actual measurement parameter, Typical case's electro-magnetic transient parameter is chosen according to the unit type in machine-electricity transient model, parameter；Direct current to be studied uses and controls mould in detail Type, this model is packaged by producer, is a module for electromagnetic transient simulation routine call.

Further, in described step C, the power external characteristic curve of direct current to be studied is and passes through under fault disturbance to be studied Direct current active power that electromagnetic transient simulation obtains and reactive capability curve.

Further, in described step D, replace DC Model to be studied, the power of constant power load model with constant power load model model Represent the Power Exchange of straight-flow system and change of current bus containing wave filter, to flow out change of current bus as positive direction, constant power load model mould Type expressions below group represents:

$\left\{\begin{array}{c}{P}_{L0}=-P_{D0}\\ Q_{L0}=Q_{D0}-Q_{F0}\end{array}\right.----\left(1\right);$

In formula, P_L0、Q_L0It is respectively the active power of constant power load model, reactive power in trend；P_D0For direct current to be studied Active power, Q_D0The reactive power of DC consumption to be studied, Q_F0Reactive power for DC filter；P_D0、Q_F0With stream Entering change of current bus is positive direction, Q_D0To flow out change of current bus as positive direction.

Further, in described step E, the power external characteristic curve treating researching DC carries out little step-length sampling, bent with ladder Line matching, power external characteristic curve expressions below group represents:

$\left\{\begin{array}{c}{P}_{\mathrm{LS}}\left(t\right)=P_L\left(\mathrm{k\&Delta;T}\right)\\ Q_{\mathrm{LS}}\left(t\right)=Q_L\left(\mathrm{k\&Delta;T}\right)\end{array},\mathrm{k\&Delta;T}\&le;t<(k+1)\mathrm{\&Delta;T},k=\mathrm{0,1,2},...,n---\left(2\right);\right.$

In formula, P_L(t)、Q_LT () is respectively meritorious, the idle curve of direct current to be studied, P_LS(t)、Q_LST () respectively uses rank Curve after ladder curve matching, Δ T is sampling step length, and n is number of samples；Number of samples is less than electromechanical transient simulation model one The cutting load operation number supported in secondary emulation.

Further, in described step F, each ladder for matched curve is respectively provided with a cutting load operation, expression formula group As follows:

$\left\{\begin{array}{c}{\mathrm{\&Delta;P}}_L\left(t_k\right)=-(P_{\mathrm{LS}}\left(t_k\right)-P_{\mathrm{LS}}\left(t_{k-1}\right))\\ \mathrm{\&Delta;}{Q}_L\left(t_k\right)=-Q_{\mathrm{LS}}\left(t_k\right)-Q_{\mathrm{LS}}(t_k-1)\end{array}\right.---\left(3\right);$

In formula, Δ P_L(t_k)、ΔQ_L(t_k) it is respectively t_kThe cutting load amount in moment；t_kFor kth sampling instant, t_k=k Δ T, K=2 ..., n；Multiple cutting loads operation of the fault identical with step C and generation is set, bulk power grid is carried out electromechanical transient and imitates True analysis.

Compared with the prior art, the present invention reaches to provide the benefit that:

The present invention can operate with in the theoretical research of power system, simulation analysis and operation control, is provided by electromagnetic transient simulation Direct-current external characteristic curve organically combines with bulk power grid electromechanical transient simulation, and the bulk power grid containing straight-flow system can effectively carry out emulation point Analysis, solves direct current machine-electricity transient model and is difficult to a difficult problem for accurate simulation direct current dynamic response characteristic, beneficially systematic analysis, operation Personnel grasp the bulk power grid operation characteristic containing straight-flow system, improve power network safety operation level.

Accompanying drawing explanation

Fig. 1 is that the direct solenoid transient state that the present invention provides is gained merit curve chart；

Fig. 2 is the idle curve chart of direct solenoid transient state that the present invention provides；

Fig. 3 is that the direct current with impact load matching that the present invention provides is gained merit curve chart；

Fig. 4 is the idle curve chart of direct current using impact load matching that the present invention provides；

Fig. 5 is bulk power grid the whole network maximum work angular difference curve chart that the present invention provides；

Fig. 6 is the direct current near region busbar voltage curve chart that the present invention provides；

Fig. 7 is the flow chart that the Bulk power system simulation based on direct-current external characteristic matching that the present invention provides analyzes method.

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 present invention provide Bulk power system simulation based on direct-current external characteristic matching analyze method flow chart as it is shown in fig. 7, comprises under State step:

Step A: retain DC converter station to be studied and near region part bus, bulk power grid machine-electricity transient model remainder is carried out Equivalence, sets up equivalent mini system.In bulk power grid machine-electricity transient model, centered by the change of current bus of direct current to be studied, retain The multistage outlet near region, carries out Thevenin's equivalence to the electrical network remainder locating multistage outlet at the bus of border, sets up and comprises direct current Near region system and the equivalent mini system of Thevenin's equivalence power supply.

Step B: build the electrical-magnetic model of equivalent mini system, direct current to be studied uses detailed Controlling model.Build equivalent little The electrical-magnetic model of system；Wherein, the circuit in electrical-magnetic model, electromotor, transformator, secondary capacitor and low pressure The alternating current equipments such as reactor use actual measurement parameter, if without actual measurement parameter, according to the unit type in machine-electricity transient model, parameter choosing Take typical case's electro-magnetic transient parameter；Direct current to be studied uses detailed Controlling model, and this model is typically packaged by producer, is one It is available for the module that electromagnetic transients program calls.

Step C: for fault to be studied, equivalent mini system is carried out electromagnetic transient simulation, obtains outside the power of direct current to be studied Characteristic curve；The power external characteristic curve of direct current to be studied is and is obtained by electromagnetic transient simulation under fault disturbance to be studied Direct current active power and reactive capability curve.

Step D: amendment bulk power grid machine-electricity transient model, replaces DC Model to be studied with constant power load model model, adjusts big electricity Network operation mode so that it is consistent with the equivalent mini system in electromagnetic transient simulation.Direct current to be studied is replaced with constant power load model model Model, the power of constant power load model represents the Power Exchange of the straight-flow system containing wave filter and change of current bus, to flow out change of current bus For positive direction, constant power load model model expressions below group represents:

$\left\{\begin{array}{c}{P}_{L0}=-P_{D0}\\ Q_{L0}=Q_{D0}-Q_{F0}\end{array}\right.----\left(1\right);$

In formula, P_L0、Q_L0It is respectively the active power of constant power load model, reactive power in trend；P_D0For direct current to be studied Active power, Q_D0The reactive power of DC consumption to be studied, Q_F0Reactive power for DC filter；P_D0、Q_F0With stream Entering change of current bus is positive direction, Q_D0To flow out change of current bus as positive direction.

Step E: be simulated with segmentation impact load in bulk power grid, under operating mode identical with step C, bulk power grid carried out machine Electricity transient emulation analysis.The power external characteristic curve treating researching DC carries out little step-length sampling, uses staircase curve matching, power External characteristic curve expressions below group represents:

$\left\{\begin{array}{c}{P}_{\mathrm{LS}}\left(t\right)=P_L\left(\mathrm{k\&Delta;T}\right)\\ Q_{\mathrm{LS}}\left(t\right)=Q_L\left(\mathrm{k\&Delta;T}\right)\end{array},\mathrm{k\&Delta;T}\&le;t<(k+1)\mathrm{\&Delta;T},k=\mathrm{0,1,2},...,n---\left(2\right);\right.$

In formula, P_L(t)、Q_LT () is respectively meritorious, the idle curve of direct current to be studied, P_LS(t)、Q_LST () respectively uses rank Curve after ladder curve matching, Δ T is sampling step length, and n is number of samples；Number of samples is less than electromechanical transient simulation model one The cutting load operation number supported in secondary emulation.

Step F: each ladder for matched curve is respectively provided with a cutting load operation, and expression formula group is as follows:

$\left\{\begin{array}{c}{\mathrm{\&Delta;P}}_L\left(t_k\right)=-(P_{\mathrm{LS}}\left(t_k\right)-P_{\mathrm{LS}}\left(t_{k-1}\right))\\ \mathrm{\&Delta;}{Q}_L\left(t_k\right)=-Q_{\mathrm{LS}}\left(t_k\right)-Q_{\mathrm{LS}}(t_k-1)\end{array}\right.---\left(3\right);$

In formula, Δ P_L(t_k)、ΔQ_L(t_k) it is respectively t_kThe cutting load amount in moment；t_kFor kth sampling instant, t_k=k Δ T, K=2 ..., n；Multiple cutting loads operation of the fault identical with step C and generation is set, bulk power grid is carried out electromechanical transient and imitates True analysis.

Embodiment

The present embodiment illustrates with certain interconnected network for emulation embodiment.

In this electrical network, certain direct current restarts successfully the simulation calculation example as the present invention, the reasonability of the checking present invention for three times.

The first step: bulk power grid carries out equivalence, sets up the equivalent mini system electrical-magnetic model containing detailed DC Model.

Second step: equivalent mini system is carried out direct current and restarts successfully electromagnetic transient simulation three times, obtain dc power external characteristics bent Line, as shown in Figure 1 and Figure 2.

3rd step: DC Model to be studied for bulk power grid is changed into constant power load model, and adjusts the method for operation with reference to equivalent mini system.

4th step: employing 0.0043s is step-length, with staircase curve analog DC power external characteristic curve, uses segmentation in bulk power grid Impact load analog DC external characteristics, power external characteristic curve expressions below group represents:

$\left\{\begin{array}{c}{P}_{\mathrm{LS}}\left(t\right)=P_L\left(\mathrm{k\&Delta;T}\right)\\ Q_{\mathrm{LS}}\left(t\right)=Q_L\left(\mathrm{k\&Delta;T}\right)\end{array},\mathrm{k\&Delta;T}\&le;t<(k+1)\mathrm{\&Delta;T},k=\mathrm{0,1,2},...,n---\left(2\right);\right.$

In formula, P_L(t)、Q_LT () is respectively meritorious, the idle curve of direct current to be studied, P_LS(t)、Q_LST () respectively uses rank Curve after ladder curve matching, Δ T is sampling step length, and n is number of samples；Number of samples is less than electromechanical transient simulation model one The cutting load operation number supported in secondary emulation, as shown in Figure 3,4.

5th step: each ladder for matched curve is respectively provided with a cutting load operation, and expression formula group is as follows:

$\left\{\begin{array}{c}{\mathrm{\&Delta;P}}_L\left(t_k\right)=-(P_{\mathrm{LS}}\left(t_k\right)-P_{\mathrm{LS}}\left(t_{k-1}\right))\\ \mathrm{\&Delta;}{Q}_L\left(t_k\right)=-Q_{\mathrm{LS}}\left(t_k\right)-Q_{\mathrm{LS}}(t_k-1)\end{array}\right.---\left(3\right);$

In formula, Δ P_L(t_k)、ΔQ_L(t_k) it is respectively t_kThe cutting load amount in moment；t_kFor kth sampling instant, t_k=k Δ T, K=2 ..., n；Multiple cutting loads operation of the fault identical with step C and generation is set, bulk power grid is carried out electromechanical transient and imitates True analysis.As shown in Figure 5,6, Fig. 5 is the whole network maximum work angular difference curve to simulation result, and Fig. 6 is direct current near region busbar voltage Curve.

Finally should be noted that: above example is only in order to illustrate that technical scheme is not intended to limit, although reference The present invention has been described in detail by above-described embodiment, those of ordinary skill in the field it is understood that still can to this Invention detailed description of the invention modify or equivalent, and without departing from spirit and scope of the invention any amendment or etc. With replacing, it all should be contained in the middle of scope of the presently claimed invention.

Claims (5)

1. a Bulk power system simulation based on direct-current external characteristic matching analyzes method, it is characterised in that described method includes walking as follows Rapid:

Step A: in bulk power grid machine-electricity transient model, retains direct current near region to be studied system, wears electrical network remainder Dimension south is equivalent, sets up equivalent mini system；

Step B: build the electrical-magnetic model of equivalent mini system, direct current to be studied uses detailed Controlling model；

Step C: for fault to be studied, equivalent mini system is carried out electromagnetic transient simulation, obtains outside the power of direct current to be studied Characteristic curve；

Step D: amendment bulk power grid machine-electricity transient model, replaces DC Model to be studied with constant power load model model, adjusts big electricity Network operation mode so that it is consistent with the equivalent mini system in electromagnetic transient simulation；

Step E: the power external characteristic curve treating researching DC carries out little step-length sampling, uses staircase curve matching；

Step F: be respectively provided with a cutting load operation for each ladder of matched curve, with step C same fault under to greatly Electrical network carries out electromechanical transient simulation analysis；

In described step A, in bulk power grid machine-electricity transient model, centered by the change of current bus of direct current to be studied, retain near region Multistage outlet, carries out Thevenin's equivalence to the electrical network remainder locating multistage outlet at the bus of border, sets up and comprises direct current near region System and the equivalent mini system of Thevenin's equivalence power supply；

In described step B, build the electrical-magnetic model of equivalent mini system；Wherein, the circuit in electrical-magnetic model, generating Machine, transformator, secondary capacitor and low tension reactor alternating current equipment use actual measurement parameter, if without actual measurement parameter, temporary according to electromechanics Unit type in states model, parameter choose typical case's electro-magnetic transient parameter；Direct current to be studied uses detailed Controlling model, and this is detailed Controlling model is packaged by producer, is a module for electromagnetic transient simulation routine call.

2. Bulk power system simulation as claimed in claim 1 analyzes method, it is characterised in that in described step C, to be studied directly The power external characteristic curve of stream is under fault disturbance to be studied the direct current active power obtained by electromagnetic transient simulation and idle Power curve.

3. Bulk power system simulation as claimed in claim 1 analyzes method, it is characterised in that in described step D, use invariable power Load model replaces DC Model to be studied, and the power of constant power load model represents the merit of the straight-flow system containing wave filter and change of current bus Rate exchanges, and to flow out change of current bus as positive direction, constant power load model model expressions below group represents:

$\left\{\begin{array}{c}{P}_{L0}=-P_{D0}\\ Q_{L0}=Q_{D0}-Q_{F0}\end{array}\right.---\left(1\right);$

In formula, P_L0、Q_L0It is respectively the active power of constant power load model, reactive power in trend；P_D0For direct current to be studied Active power, Q_D0The reactive power of DC consumption to be studied, Q_F0Reactive power for DC filter；P_D0、Q_F0With stream Entering change of current bus is positive direction, Q_D0To flow out change of current bus as positive direction.

4. Bulk power system simulation as claimed in claim 1 analyzes method, it is characterised in that in described step E, to be studied directly The power external characteristic curve of stream carries out little step-length sampling, uses staircase curve matching, power external characteristic curve expressions below group table Show:

$\left\{\begin{array}{c}{P}_{LS}\left(t\right)=P_L\left(k\mathrm{\&Delta;}T\right)\\ Q_{LS}\left(t\right)=Q_L\left(k\mathrm{\&Delta;}T\right)\end{array}\right.,k\mathrm{\&Delta;}T\&le;t<(k+1)\mathrm{\&Delta;}T,k=0,1,2,...,n---\left(2\right);$

In formula, P_L(t)、Q_LT () is respectively meritorious, the idle curve of direct current to be studied, P_LS(t)、Q_LST () respectively uses rank Curve after ladder curve matching, Δ T is sampling step length, and n is number of samples；Number of samples is less than electromechanical transient simulation model one The cutting load operation number supported in secondary emulation.

5. Bulk power system simulation as claimed in claim 1 analyzes method, it is characterised in that in described step F, bent for matching Each ladder of line is respectively provided with a cutting load operation, and expression formula group is as follows:

$\left\{\begin{array}{c}{\mathrm{\&Delta;P}}_L\left(t_k\right)=-\left(P_{LS}\left(t_k\right)-P_{LS}\left(t_{k-1}\right)\right)\\ {\mathrm{\&Delta;Q}}_L\left(t_k\right)=Q_{LS}\left(t_k\right)-Q_{LS}\left(t_{k-1}\right)\end{array}\right.---\left(3\right);$

In formula, Δ P_L(t_k)、ΔQ_L(t_k) it is respectively t_kThe cutting load amount in moment；t_kFor kth sampling instant, t_k=k Δ T, K=2 ..., n；P_LS(t_k)、P_LS(t_k-1) it is respectively t_kMoment and t_k-1With the meritorious curve after staircase curve matching, Q_LS(t_k)、 Q_LS(t_k-1) it is respectively t_kMoment and t_k-1With the idle curve after staircase curve matching；Δ T is sampling step length；With step C phase Under same fault, the operation of multiple cutting load is set, bulk power grid is carried out electromechanical transient simulation analysis.