CN102982203B - Optimization method of parameters of small step switch model - Google Patents

Abstract

The invention provides an optimization method of parameters of a small step switch model. The optimization method includes that analyzing stability ranges of errors of a small step switch, ensuring selectable range of the parameters of the small step switch model; setting up equivalent damping coefficient model of the small step switch model, ensuring mutual relationship of capacitor and inductance of the small step switch under a cut-off state; setting up a switch loss module of the small step switch, using the loss to measure the errors of the switch, and ensuring relationship between equivalent admittance of the small step switch and the equivalent admittance of an external circuit through optimizing the loss; and setting up a specific parameter arrangement of the small step switch model. The optimization method of the parameters of the small step switch model solves the problems that an existing small step switch model can not ensure model parameters and then accuracy is affected, can ensure the parameter model of the small step switch, and simultaneously ensures that the loss of the small step switch in simulation is reduced to the minimum, and improves accuracy of small step simulation.

Description

The parameter optimization method of little step-length switch models

Technical field

The invention belongs to electric switch field, be specifically related to a kind of parameter optimization method of little step-length switch models.

Background technology

In the emulation of little step-length the equivalent switch of capacitor and inductor with the parasitic character of switch for starting point.The characteristic of switch when disconnecting can be simulated with electric capacity, can come equivalent with inductance in closing course, as long as ensure that the electric capacity of switch has similar Dommol Equivalent admittance with inductance characteristic under particular dummy step-length, then the admittance battle array of switching over operation without the need to revising system, improves the efficiency of system emulation.

At present, the simulation step length of high-frequency current transformer is 1-3 microsecond (us), and the parameter of the switch L/C model defined according to this simulation step length has larger difference with stray capacitance and inductance parameters; If directly use the parasitic parameter of switch, cause step-length little of nanosecond (ns) order of magnitude, real-time realization is more difficult.So the parameter of little step-length switch models is the foundation do not determined.And little step-length switch models parameter can affect transient error, the emulation stability and steady-state loss of little step-length switch.

Summary of the invention

For overcoming above-mentioned defect, the invention provides a kind of parameter optimization method of little step-length switch models, overcoming existing little step-length switch models cannot Confirming model parameter and affect the problem of model emulation precision, establish the detailed modeling formula of little step length algorithm, not only can determine the parameter model of little step-length switch, can ensure that the loss in simulations of little step-length switch is minimum simultaneously, improve the accuracy of little step-length emulation.

For achieving the above object, the invention provides a kind of parameter optimization method of little step-length switch models, its improvements are, described method comprises the steps:

(1). analyze the stable region of little step-length switch error, determine the parameter range of choices of little step-length switch models;

(2). set up the Equivalent damping coefficient model of little step-length switch models, determine the mutual relationship of the capacitor and inductor under the state of cut-offfing of little step-length switch;

(3). set up the switching loss model of little step-length switch, switch error is weighed in service wear, and determines the Equivalent admittance of little step-length switch and the relation of external circuit Equivalent admittance by optimizing loss;

(4). the design parameter setting up little step-length switch models is arranged.

In optimal technical scheme provided by the invention, in described step 1, analyze the stable region of little step-length switch, set up the transient error model of little step-length switch, obtain the transient error of the little step-length switch using transport function to represent; Determine the feasible zone of little step-length switch models parameter according to the criterion of system stability simultaneously:

$\left\{\begin{array}{c}R\∈(R_1,R_2)\\ L\∈(L_1,L_2)\\ C\∈(C_1,C_2)\end{array}\right..$

In second optimal technical scheme provided by the invention, in described step 2, under the integration of Gear-3, obtain the equivalent damping model of little step-length switch models through the equivalence of numerical integration, as shown in Figure 1.Meanwhile, the relation of the equivalent resistance ratio σ and circuit ratio of damping δ that have also been obtained resistance R and electric capacity C is shown below:

${\mathrm{\δ}}^2=\frac{4{(\mathrm{\σ}-2)}^2}{(79-5\mathrm{\σ})(\mathrm{\σ}+1)}$

In 3rd optimal technical scheme provided by the invention, in described step 3, set up the switching loss model of little step-length switch, switch error is weighed in service wear, and determine the Equivalent admittance of little step-length switch and the relation of external circuit Equivalent admittance by optimizing loss, under the integration method of Gear-3, switching loss model is shown below:

$\mathrm{\η}=\frac{4}{{\mathrm{\τ}}^2}\frac{4k}{3N\·(1+\mathrm{\σ})}(1-\frac{9}{256}\frac{{(1+\mathrm{\σ})}^4}{{(1+k)}^2})+\frac{4}{{\mathrm{\τ}}^2}\frac{2}{3N\·k}(1-\frac{9}{16{(\frac{1}{k}+1)}^2})$

Wherein, k represents the equivalent admittance of switch and the ratio of external circuit, and σ represents the equivalent resistance ratio of resistance R and electric capacity C, and N represents the step number of little step-length simulation run in a switch periods; η represents the proportion of goods damageds; τ represents the dutycycle of transverter.

In 4th optimal technical scheme provided by the invention, in described step 4, the value of the value of σ and the k formula substituted into below is tried to achieve the optimum configurations of little step-length switch models:

$C=\frac{2}{1+\mathrm{\σ}}\frac{\mathrm{\Δt}}{c0}k\·\frac{\mathrm{Is}}{V}$

$L=\frac{\mathrm{\Δt}}{c0\·k}\frac{V}{\mathrm{Is}}$

$R=\frac{1-\mathrm{\σ}}{2}k\·\frac{\mathrm{Is}}{V}$

C0 represents the constant of a numerical algorithm, and Δ t represents simulation step length, and Is represents the running current of switch, and V represents the rating operating voltage of switch.

Compared with the prior art, the parameter optimization method of a kind of little step-length switch models provided by the invention, overcoming existing little step-length switch models cannot Confirming model parameter and affect the problem of model emulation precision, establish the detailed modeling formula of little step length algorithm, not only can determine the parameter model of little step-length switch, simultaneously can ensure that the loss in simulations of little step-length switch is minimum, improve the accuracy rate that little step-length emulates, and make little step-length switch models parameter defined foundation; Establish the emulation loss model of little step-length switch models; The little step-length switch models determined according to this method has the switching loss of optimization.

Accompanying drawing explanation

Fig. 1 is the equivalent damping model under numerical integration.

Embodiment

The parameter optimization method of little step-length switch models, comprises the steps:

(1). analyze the stable region of little step-length switch error, determine the parameter range of choices of little step-length switch models;

(2). set up the Equivalent damping coefficient model of little step-length switch models, determine the mutual relationship of the capacitor and inductor under the state of cut-offfing of little step-length switch;

(3). set up the switching loss model of little step-length switch, switch error is weighed in service wear, and determines the Equivalent admittance of little step-length switch and the relation of external circuit Equivalent admittance by optimizing loss;

(4). the design parameter setting up little step-length switch models is arranged.

In described step 1, analyze the stable region of little step-length switch, set up the transient error model of little step-length switch, obtain the transient error of the little step-length switch using transport function to represent; Determine the feasible zone of little step-length switch models parameter according to the criterion of system stability simultaneously:

$\left\{\begin{array}{c}R\∈(R_1,R_2)\\ L\∈(L_1,L_2)\\ C\∈(C_1,C_2)\end{array}\right..$

In described step 2, under the integration of Gear-3, obtain the equivalent damping model of little step-length switch models through the equivalence of numerical integration, as shown in Figure 1.Meanwhile, the relation of the equivalent resistance ratio σ and circuit ratio of damping δ that have also been obtained resistance R and electric capacity C is shown below:

${\mathrm{\δ}}^2=\frac{4{(\mathrm{\σ}-2)}^2}{(79-5\mathrm{\σ})(\mathrm{\σ}+1)}$

In described step 3, set up the switching loss model of little step-length switch, switch error is weighed in service wear, and determines the Equivalent admittance of little step-length switch and the relation of external circuit Equivalent admittance by optimizing loss, under the integration method of Gear-3, switching loss model is shown below:

$\mathrm{\η}=\frac{4}{{\mathrm{\τ}}^2}\frac{4k}{3N\·(1+\mathrm{\σ})}(1-\frac{9}{256}\frac{{(1+\mathrm{\σ})}^4}{{(1+k)}^2})+\frac{4}{{\mathrm{\τ}}^2}\frac{2}{3N\·k}(1-\frac{9}{16{(\frac{1}{k}+1)}^2})$

Wherein, k represents the equivalent admittance of switch and the ratio of external circuit, and σ represents the equivalent resistance ratio of resistance R and electric capacity C, and N represents the step number of little step-length simulation run in a switch periods; η represents the proportion of goods damageds; τ represents the dutycycle of transverter.

In described step 4, the value of the value of σ and the k formula substituted into below is tried to achieve the optimum configurations of little step-length switch models:

$C=\frac{2}{1+\mathrm{\σ}}\frac{\mathrm{\Δt}}{c0}k\·\frac{\mathrm{Is}}{V}$

$L=\frac{\mathrm{\Δt}}{c0\·k}\frac{V}{\mathrm{Is}}$

$R=\frac{1-\mathrm{\σ}}{2}k\·\frac{\mathrm{Is}}{V}$

C0 represents the constant of a numerical algorithm, and Δ t represents simulation step length, and Is represents the running current of switch, and V represents the rating operating voltage of switch.

Be described further by the parameter optimization method of following examples to little step-length switch models.

As shown in Figure 1, the cardinal rule of the little step-length model modeling of proposition and parameter selection method, have versatility, and in different numerical integration methods, this method is all applicable.Gear-3 integral method is selected to carry out the concrete embodiment of this method.

Step 1, analyzes the stable region of little step-length switch error, determines the parameter range of choices of little step-length switch models.Under the integration method of Gear-3, in any case the parameter change of switch models, the eigenwert of error system is all in stable region, so little step-length switch models error does not exist the instability that parameter causes.

Step 2, sets up the Equivalent damping coefficient model of little step-length switch models, determines the resistance R of the little step-length switch under certain ratio of damping δ and the equivalent resistance ratio σ of electric capacity C according to the damping characteristic of R, L, C series circuit.The size of this ratio of damping δ must meet the resonance that can not produce circuit in circuit simulation, and general damping coefficient δ requires that size is 0.9-1.3.But, the size being aware of damping can not know the circuit parameter of little step-length switch models, the present invention have studied the equivalent resistance ratio σ of resistance R and electric capacity C and the relation of circuit ratio of damping δ, determines the mutual relationship of the capacitor and inductor under the state of cut-offfing of little step-length switch.Under different integration methods, the parameter of Equivalent damping coefficient model is different.Under the integration of Gear-3, obtain the equivalent damping model of little step-length switch models through the equivalence of numerical integration, as shown in Figure 1.Meanwhile, the relation of the equivalent resistance ratio σ and circuit ratio of damping δ that have also been obtained resistance R and electric capacity C is shown below.

${\mathrm{\δ}}^2=\frac{4{(\mathrm{\σ}-2)}^2}{(79-5\mathrm{\σ})(\mathrm{\σ}+1)}$

Step 3, set up the switching loss model of little step-length switch, switch error is weighed in service wear, and determines the Equivalent admittance of little step-length switch and the relation of external circuit Equivalent admittance by optimizing loss.Under the integration method of Gear-3, switching loss model is shown below:

$\mathrm{\η}=\frac{4}{{\mathrm{\τ}}^2}\frac{4k}{3N\·(1+\mathrm{\σ})}(1-\frac{9}{256}\frac{{(1+\mathrm{\σ})}^4}{{(1+k)}^2})+\frac{4}{{\mathrm{\τ}}^2}\frac{2}{3N\·k}(1-\frac{9}{16{(\frac{1}{k}+1)}^2})$

In above formula, k represents the equivalent admittance of switch and the ratio of external circuit, and σ represents the equivalent resistance ratio of resistance R and electric capacity C, and N represents the step number of little step-length simulation run in a switch periods.

According to above formula, the optimization of the loss of little step-length switch is a single object optimization, uses ripe optimization method just can obtain equivalent admittance when proportion of goods damageds η is minimum and the ratio k of external circuit and the relation of σ and N.And the equivalent resistance ratio σ of resistance R and electric capacity C has obtained in previous step, and in switch periods, the step number N of little step-length simulation run is the known amount of simulation example.

Be 1 μ s in simulation step length, when switching frequency 2000Hz, N=500, dutycycle gets desirable 0.9.Now by single object optimization algorithm, can in the hope of when k=0.6325, loss η minimum 0.0897.

Step 4, according to the conclusion of above step, the design parameter setting up little step-length switch models is arranged.The value of the k of the value of the σ of step 2 and the step 3 formula substituted into below is tried to achieve the optimum configurations of little step-length switch models.

$C=\frac{2}{1+\mathrm{\σ}}\frac{\mathrm{\Δt}}{c0}k\·\frac{\mathrm{Is}}{V}$

$L=\frac{\mathrm{\Δt}}{c0\·k}\frac{V}{\mathrm{Is}}$

$R=\frac{1-\mathrm{\σ}}{2}k\·\frac{\mathrm{Is}}{V}$

It is to be understood that content of the present invention and embodiment are intended to the practical application proving technical scheme provided by the present invention, should not be construed as limiting the scope of the present invention.Those skilled in the art inspired by the spirit and principles of the present invention, can do various amendment, equivalent replacement or improve.But these changes or amendment are all in the protection domain that application is awaited the reply.

Claims (3)

1. a parameter optimization method for little step-length switch models, is characterized in that, described method comprises the steps:

(1). analyze the stable region of little step-length switch error, determine the parameter range of choices of little step-length switch models;

(2). set up the Equivalent damping coefficient model of little step-length switch models, determine the mutual relationship of the capacitor and inductor under the state of cut-offfing of little step-length switch, Gear ?3 integration under, obtain the equivalent damping model of little step-length switch models through the equivalence of numerical integration, the relation of the equivalent resistance ratio σ and circuit ratio of damping δ that simultaneously have also been obtained resistance R and electric capacity C is shown below:

${\mathrm{\δ}}^2=\frac{{4(\mathrm{\σ}-2)}^2}{(79-5\mathrm{\σ})(\mathrm{\σ}+1)};$

(3). set up the switching loss model of little step-length switch, switch error is weighed in service wear, and determine the Equivalent admittance of little step-length switch and the relation of external circuit Equivalent admittance by optimizing loss, under the integration method of Gear ?3, switching loss model is shown below:

$\mathrm{\η}=\frac{4}{{\mathrm{\τ}}^2}\frac{4k}{3N\·(1+\mathrm{\σ})}(1-\frac{9}{256}\frac{{(1+\mathrm{\σ})}^4}{{(1+k)}^2})+\frac{4}{{\mathrm{\τ}}^2}\frac{2}{3N\·k}(1-\frac{9}{16{(\frac{1}{k}+1)}^2})$

Wherein, k represents the equivalent admittance of switch and the ratio of external circuit, and σ represents the equivalent resistance ratio of resistance R and electric capacity C, and N represents the step number of little step-length simulation run in a switch periods; η represents the proportion of goods damageds; τ represents the dutycycle of transverter;

(4). the design parameter setting up little step-length switch models is arranged.

2. method according to claim 1, is characterized in that, in described step 1, analyzes the stable region of little step-length switch, sets up the transient error model of little step-length switch, obtains the transient error of the little step-length switch using transport function to represent; Determine the feasible zone of little step-length switch models parameter according to the criterion of system stability simultaneously:

$\left\{\begin{array}{c}R\∈(R_{\min },R_{\max })\\ L\∈(L_{\min },L_{\max })\\ C\∈(C_{\min },C_{\max })\end{array}\right.$

Wherein R represents the value of resistance, and Rmin represents the lower bound of feasible zone, and Rmax represents the upper bound of feasible zone, and L represents the value of inductance, and C represents the value of electric capacity.

3. method according to claim 1, is characterized in that, in described step 4, the value of the value of σ and the k formula substituted into below is tried to achieve the optimum configurations of little step-length switch models:

$C=\frac{2}{1+\mathrm{\σ}}\frac{\mathrm{\Δt}}{c0}k\·\frac{\mathrm{Is}}{V}$

$L=\frac{\mathrm{\Δt}}{c0\·k}\frac{V}{\mathrm{Is}}$

$R=\frac{1-\mathrm{\σ}}{2}k\·\frac{\mathrm{Is}}{V}$

C0 represents the constant of a numerical algorithm, and Δ t represents simulation step length, and Is represents the running current of switch, and V represents the rating operating voltage of switch.