CN102982203A - 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 the long switch model of small step

Technical field

The invention belongs to the electric switch field, be specifically related to the parameter optimization method of the long switch model of a kind of small step.

Background technology

The equivalent switch of capacitor and inductor is take the parasitic character of switch as starting point in the long emulation of small step.The characteristic of switch when disconnecting can be simulated with electric capacity, can come equivalent with inductance in the closing course, under the particular dummy step-length, has similar Dommol Equivalent admittance as long as guarantee the electric capacity of switch with inductance characteristic, then the switching over operation need not the admittance battle array of the system of revising, and has promoted the efficient of system emulation.

At present, the simulation step length of high-frequency current transformer is 1-3 microsecond (us), with stray capacitance and inductance parameters larger difference is arranged on the parameter according to the switch L/C model of this simulation step length definition; If directly use the parasitic parameter of switch, cause step-length little of nanosecond (ns) order of magnitude, real-time realization is difficulty relatively.So the parameter of the long switch model of small step is not have definite foundation.And the long switching molding shape parameter of small step can affect transient error, emulation stability and the steady-state loss of the long switch of small step.

Summary of the invention

For overcoming defects, the invention provides the parameter optimization method of the long switch model of a kind of small step, overcome that the long switch model of existing small step can't be determined model parameter and the problem that affects the model emulation precision, set up the detailed modeling formula of little step length algorithm, not only can determine the parameter model of the long switch of small step, can guarantee simultaneously that the loss of the long switch of small step in emulation is minimum, improve the accuracy of the long emulation of small step.

For achieving the above object, the invention provides the parameter optimization method of the long switch model of a kind of small step, its improvements are that described method comprises the steps:

(1). analyze the stable region of the long switch error of small step, determined the optional scope of parameter of the long switch model of small step;

(2). set up the Equivalent damping coefficient model of the long switch model of small step, determine the mutual relationship of the capacitor and inductor under the state that cut-offs of the long switch of small step;

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

(4). set up the design parameter setting of the long switch model of small step.

In the optimal technical scheme provided by the invention, in described step 1, analyze the stable region of the long switch of small step, set up the transient error model of the long switch of small step, obtain using the transient error of the long switch of small step that transport function represents; Determine simultaneously the feasible zone of the long switching molding shape parameter of small step according to the criterion of system stability:

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

In the second optimal technical scheme provided by the invention, in described step 2, under the integration of Gear-3, the equivalence of process numerical integration has obtained the equivalent damping model of the long switch model of small step, as shown in Figure 1.Simultaneously, also having obtained the equivalent resistance ratio σ of resistance R and capacitor C and the relation of circuit ratio of damping δ is shown below:

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

In the 3rd optimal technical scheme provided by the invention, in described step 3, set up the switching loss model of the long switch of small step, the switch error is weighed in service wear, and determine the relation of Equivalent admittance and the external circuit Equivalent admittance of the long switch of small step by optimizing loss, under the integration method of Gear-3, the 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 capacitor C, and N represents the step number of the long simulation run of small step in the switch periods; η represents the proportion of goods damageds; τ represents the dutycycle of transverter.

In the 4th optimal technical scheme provided by the invention, in described step 4, the formula below the value substitution of the value of σ and k is tried to achieve the parameter setting of the long switch model of small step:

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

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

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

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 the long switch model of a kind of small step provided by the invention, overcome that the long switch model of existing small step can't be determined model parameter and the problem that affects the model emulation precision, set up the detailed modeling formula of little step length algorithm, not only can determine the parameter model of the long switch of small step, can guarantee simultaneously that the loss of the long switch of small step in emulation is minimum, improve the accuracy rate of the long emulation of small step, and make the foundation that defined of the long switching molding shape parameter of small step; Set up the emulation loss model of the long switch model of small step; The switching loss that optimization is arranged according to the definite long switch model of small step of this method.

Description of drawings

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

Embodiment

The parameter optimization method of the long switch model of small step comprises the steps:

(1). analyze the stable region of the long switch error of small step, determined the optional scope of parameter of the long switch model of small step;

(2). set up the Equivalent damping coefficient model of the long switch model of small step, determine the mutual relationship of the capacitor and inductor under the state that cut-offs of the long switch of small step;

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

(4). set up the design parameter setting of the long switch model of small step.

In described step 1, analyze the stable region of the long switch of small step, set up the transient error model of the long switch of small step, obtain using the transient error of the long switch of small step that transport function represents; Determine simultaneously the feasible zone of the long switching molding shape parameter of small step according to the criterion of system stability:

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

In described step 2, under the integration of Gear-3, the equivalence of process numerical integration has obtained the equivalent damping model of the long switch model of small step, as shown in Figure 1.Simultaneously, also having obtained the equivalent resistance ratio σ of resistance R and capacitor C and the relation of circuit ratio of damping δ 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 the long switch of small step, the switch error is weighed in service wear, and determines the relation of Equivalent admittance and the external circuit Equivalent admittance of the long switch of small step by optimizing loss, under the integration method of Gear-3, the 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 capacitor C, and N represents the step number of the long simulation run of small step in the switch periods; η represents the proportion of goods damageds; τ represents the dutycycle of transverter.

In described step 4, the formula below the value substitution of the value of σ and k is tried to achieve the parameter setting of the long switch model of small step:

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

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

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

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 the long switch model of small step.

As shown in Figure 1, cardinal rule and the parameter selection method of the long model modeling of small step of proposition have versatility, and in different numerical integration methods, this method all is suitable for.Select the Gear-3 integral method to carry out the implementation example of this method.

Step 1 is analyzed the stable region of the long switch error of small step, has determined the optional scope of parameter of the long switch model of small step.Under the integration method of Gear-3, in any case the parameter of switch model changes, the eigenwert of error system is all in stable region, so there be not unstable that parameter causes in the long switch model error of small step.

Step 2 is set up the Equivalent damping coefficient model of the long switch model of small step, according to R, and L, the damping characteristic of C series circuit is determined the resistance R of the long switch of small step under certain ratio of damping δ and the equivalent resistance ratio σ of capacitor C.The size of this ratio of damping δ must satisfy the resonance that can not produce circuit in the circuit simulation, and it is 0.9-1.3 that general damping coefficient δ requires size.But, the size of having known damping can not be known the circuit parameter of the long switch model of small step, the present invention has studied the relation of equivalent resistance ratio σ and the circuit ratio of damping δ of resistance R and capacitor C, has determined the mutual relationship of the capacitor and inductor under the state that cut-offs of the long switch of small step.Under different integration methods, the parameter of Equivalent damping coefficient model is different.Under the integration of Gear-3, the equivalence of process numerical integration has obtained the equivalent damping model of the long switch model of small step, as shown in Figure 1.Simultaneously, also having obtained the equivalent resistance ratio σ of resistance R and capacitor C and the relation of circuit ratio of damping δ is shown below.

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

Step 3 is set up the switching loss model of the long switch of small step, and the switch error is weighed in service wear, and determines the relation of Equivalent admittance and the external circuit Equivalent admittance of the long switch of small step by optimizing loss.Under the integration method of Gear-3, the 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 the following 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 capacitor C, and N represents the step number of the long simulation run of small step in the switch periods.

According to following formula, the optimization of the loss of the long switch of small step is a single goal optimization, and the ripe optimization method of use just can be obtained equivalent admittance and the ratio k of external circuit and the relation of σ and N in the situation of proportion of goods damageds η minimum.And the equivalent resistance ratio σ of resistance R and capacitor C has obtained in previous step, and the step number N of the long simulation run of small step is the known amount of simulation example in the switch periods.

Be 1 μ s in simulation step length, in the situation of switching frequency 2000Hz, N=500, dutycycle gets desirable 0.9.This moment can be in the hope of in the situation of k=0.6325 by the single goal optimized algorithm, loss η minimum 0.0897.

Step 4 according to the conclusion of above step, is set up the design parameter setting of the long switch model of small step.Formula below the value substitution of the k of the value of the σ of step 2 and step 3 is tried to achieve the parameter setting of the long switch model of small step.

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

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

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

What need statement is that content of the present invention and embodiment are intended to prove the practical application of technical scheme provided by the present invention, should not be construed as the restriction to protection domain of the present invention.Those skilled in the art can do various modifications, be equal to and replace or improve inspired by the spirit and principles of the present invention.But these changes or modification are all in the protection domain that application is awaited the reply.

Claims (5)

1. the parameter optimization method of the long switch model of small step is characterized in that, described method comprises the steps:

(1). analyze the stable region of the long switch error of small step, determined the optional scope of parameter of the long switch model of small step;

(2). set up the Equivalent damping coefficient model of the long switch model of small step, determine the mutual relationship of the capacitor and inductor under the state that cut-offs of the long switch of small step;

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

(4). set up the design parameter setting of the long switch model of small step.

2. method according to claim 1 is characterized in that, in described step 1, analyzes the stable region of the long switch of small step, sets up the transient error model of the long switch of small step, obtains using the transient error of the long switch of small step that transport function represents; Determine simultaneously the feasible zone of the long switching molding shape parameter of small step according to the criterion of system stability:

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

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 2, under the integration of Gear-3, the equivalence of process numerical integration has obtained the equivalent damping model of the long switch model of small step, as shown in Figure 1.Simultaneously, also having obtained the equivalent resistance ratio σ of resistance R and capacitor C and the relation of circuit ratio of damping δ is shown below:

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

4. method according to claim 1, it is characterized in that, in described step 3, set up the switching loss model of the long switch of small step, the switch error is weighed in service wear, and determine the relation of Equivalent admittance and the external circuit Equivalent admittance of the long switch of small step by optimizing loss, under the integration method of Gear-3, the 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 capacitor C, and N represents the step number of the long simulation run of small step in the switch periods; η represents the proportion of goods damageds; τ represents the dutycycle of transverter.

5. according to claim 1, it is characterized in that, in described step 4, the formula below the value substitution of the value of σ and k is tried to achieve the parameter setting of the long switch model of small step:

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

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

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

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.

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