CN113625678B - A kind of port impedance automatic simulation test method - Google Patents

Abstract

The invention discloses an automatic simulation test method for port impedance, which applies voltage to each port of a tested circuit in sequence to obtain corresponding port current, and then calculates the equivalent impedance of each port according to ohm's law. The port impedance automatic simulation test method is characterized in that an active device in a tested circuit is set to zero, and unique and fixed network identification numbers are distributed to all terminals of the tested circuit. Then, according to the test requirements, the test sequences are listed. Furthermore, an independent voltage source special for measuring the impedance of a circuit port is introduced into the circuit simulation diagram, and network identification numbers are distributed to the positive terminal and the negative terminal of the circuit simulation diagram according to a test sequence. The independent voltage source terminal is electrically connected with the network identification number of the tested circuit terminal through matching. The invention improves the efficiency of obtaining the impedance value. Meanwhile, errors caused by manual analysis or calculation errors are avoided, and the accuracy of the acquired port impedance value is improved.

Description

A kind of port impedance automatic simulation test method

technical field

The invention belongs to the technical field of aerospace power supplies, and in particular relates to an automatic simulation testing method for port impedance.

Background technique

In the functional test of the aerospace power supply controller, before power-on, it is often judged whether there is a fault in the circuit by measuring the impedance of the circuit port. When using this method, first calculate the theoretical value of the port impedance. On this basis, the measured values are compared with the theoretical values to find outliers. The traditional method to obtain the theoretical value of port impedance is: using the knowledge of circuit principle, consider each port as an input port in turn, manually analyze the equivalent circuit seen from each port, and then calculate the equivalent impedance of each port. This method takes a long time, and when the circuit is complex, it is easy to cause incorrect calculation and analysis.

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, an automatic simulation test method for port impedance is provided, which can automatically obtain the impedance value of each port in the circuit and improve the efficiency of obtaining the impedance value. At the same time, errors caused by manual analysis or calculation errors are avoided, and the accuracy of the acquired port impedance value is improved.

The object of the present invention is achieved through the following technical solutions: an automatic simulation test method for port impedance, the method includes the following steps: step 1: set all active devices in the circuit under test to zero; step 2: sequentially test the circuit under test Each terminal is assigned a unique and fixed network identification number; Step 3: Use the two terminal network labels in the circuit under test to represent a port, and formulate a port impedance test sequence; Step 4: Add an independent voltage specially used to measure the circuit port impedance source Vs, and assign network identification numbers Ni and Nj to the positive and negative terminals of the independent voltage source, so that (Ni, Nj)=Tu, where u represents the serial number of the current port to be tested; Step 5: Record the independent voltage source Vs in real time The port voltage Ui,j and port current Ii,j are calculated in real time, and the equivalent impedance Zi,j of the port composed of Ni and Nj terminals in the circuit under test is calculated in real time; Step 6: Real-time judgment of the port composed of Ni and Nj terminals in the circuit under test Whether the value of the equivalent impedance Zi,j satisfies the convergence condition; if the equivalent impedance Zi,j does not converge, go back to step 5, if the equivalent impedance Zi,j has converged, go to step 7; Step 7: Record the current The Zi,j calculated at the moment is used as the equivalent impedance of the tested port corresponding to the impedance test serial number Tu of the uth port; Step 8: Determine whether the port impedance test sequence has been executed, that is, whether u is equal to n; if u=n , it means that the execution has been completed, and the test is ended at this time.

The above-mentioned port impedance automatic simulation test method further includes: if u is not equal to n, set u=u+1, and change the values of the independent voltage source terminals Ni and Nj to make (Ni, Nj)=Tu.

In the above-mentioned port impedance automatic simulation test method, in step 1, all active devices in the circuit under test are set to zero so that all voltage sources are short-circuited and all current sources are open-circuited.

In the above-mentioned port impedance automatic simulation test method, in step 2, the network identification number of the kth terminal is denoted as Nk.

In the above-mentioned port impedance automatic simulation test method, in step 3, the port impedance test sequence is TS={T1=(Na, Nb), T2=(Nc, Nd), . . . , Tn=(Np, Nq}; wherein, n is the total number of ports to be tested, T1 is the impedance test serial number of the first port, Na is the network identification number of the a-th terminal, Nb is the network identification number of the b-th terminal, and T2 is the network identification number of the second port Impedance test serial number, Nc is the network identification number of the cth terminal, Nd is the network identification number of the dth terminal, Tn is the impedance test serial number of the nth port, Np is the network identification number of the pth terminal, and Nq is The network identification number of the qth terminal.

In the above-mentioned port impedance automatic simulation test method, in step 5, the equivalent impedance Zi,j of the port composed of Ni and Nj terminals in the circuit under test is obtained by the following formula: Zi,j=Ui,j/Ii,j.

In the above-mentioned port impedance automatic simulation test method, in step 6, the convergence condition is: when the rate of change of Zi,j is less than the preset constant δ or the simulation time is greater than or equal to the preset time T0, it is considered that Zi,j has converged, otherwise, It is considered that it has not converged.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention achieves the following effects through step 1, step 2, step 4 and step 5: calculating the equivalent impedance of each port with the help of the method of "pressurizing current flow" in the circuit principle;

(2) The present invention achieves the effect of effectively distinguishing and locating each terminal and port of the circuit under test through steps 2 and 3;

(3) The present invention achieves the following effects through step 2 and step 4: in the simulation software, the independent voltage source Vs for measuring the impedance of the circuit port and the port under test are electrically connected;

(4) Through step 3, the present invention achieves the effect of enumerating all ports to be tested to form a test sequence. On the one hand, it is convenient for subsequent automatic switching of test ports; on the other hand, it is convenient to check and check test items to avoid omissions.

(5) The present invention achieves the following effects through step 3, step 4, step 8 and step 9: after completing the impedance measurement of a certain port, the impedance of the next port is automatically measured until the test of all ports is completed;

(6) The present invention achieves the following effects through step 5: real-time monitoring of the port impedance measurement value, and obtaining its dynamic change process;

(7) The present invention achieves the following effects through steps 6 and 7: when there are capacitive and inductive elements in the circuit under test, the impedance value measured in the dynamic process of the circuit is discarded, and the impedance value measured after the circuit reaches a steady state is used. The impedance value is used as the port impedance, which is beneficial to ensure the consistency of the port impedance in multiple measurements.

(8) The present invention, through step 6, achieves the effect of avoiding too long a simulation test time for a certain port, and when the time exceeds an acceptable limit, the continuous testing of the port is stopped, thereby ensuring that the time used to complete the test sequence is controllable.

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for the purpose of illustrating preferred embodiments only and are not to be considered limiting of the invention. Also, the same components are denoted by the same reference numerals throughout the drawings. In the attached image:

1 is a schematic diagram of a simulation test circuit provided by an embodiment of the present invention;

Fig. 2 is the flow chart of execution steps of the port impedance automatic simulation test method provided by the embodiment of the present invention;

FIG. 3 is a simulation test circuit drawn in MATLAB provided by an embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be more thoroughly understood, and will fully convey the scope of the present disclosure to those skilled in the art. It should be noted that the embodiments of the present invention and the features of the embodiments may be combined with each other under the condition of no conflict. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

This embodiment provides an automatic simulation test method for port impedance, which includes the following steps:

Step 1: Set all active devices in the circuit under test to zero, that is: short-circuit all voltage sources and open-circuit all current sources;

Step 2: In the simulation file, assign a unique and fixed network identification number to each terminal in the circuit under test in turn, wherein the network identification number of the kth terminal is marked as Nk;

Step 3: Use the two terminal network labels in the circuit under test to represent a port. According to the test requirements, formulate the port test sequence TS={T1=(Na,Nb), T2=(Nc,Nd,...,Tn=(Np, Nq}, where n is the total number of ports to be tested.

Step 4: In the simulation file, add an independent voltage source Vs specially used to measure the impedance of the circuit port, and assign network identification numbers Ni and Nj to its positive and negative terminals, so that (Ni, Nj)=Tu, where u Indicates the serial number of the port currently to be tested, u=1.

Step 5: Simulation, record the port voltage Ui,j and port current Ii,j of the independent voltage source Vs in real time, and calculate the port impedance based on the principle of pressurization and current flow in the circuit principle, according to the formula Zi,j=Ui,j/ Ii,j calculate the equivalent impedance of the port composed of Ni and Nj terminals in the circuit under test;

Step 6: Determine in real time whether the value of Zi,j satisfies the convergence condition. Convergence conditions include but are not limited to the following ways: when the rate of change of Zi,j is less than a certain constant δ or the simulation time is greater than or equal to a certain time T0, it is considered that Zi,j has converged, otherwise, it is considered that it has not converged.

If Zi,j has not converged, go back to step 5 to continue the simulation, if Zi,j have converged, go to step 7;

Step 7: Record the Zi,j calculated at the current moment as the equivalent impedance of the tested port corresponding to Tu;

Step 8: Determine whether the port impedance test sequence has been executed, that is, whether u is equal to n. If u=n, it means that the execution has been completed, and the test is ended at this time; otherwise, if the execution has not been completed, go to step 9;

Step 9: Let u=u+1, and change the values of the independent source terminals Ni and Nj to make (Ni, Nj)=Tu.

According to the circuit connection mode shown in Figure 1, draw the circuit diagram shown in Figure 2 in MATLAB/Simulink. When drawing, assign the initial network identification number to the positive and negative terminals of the independent source used for impedance measurement, and at the same time, assign a unique and fixed network identification number to each terminal of the circuit under test. The "simout" module shown in Figure 2 is used to record the output voltage and current from independent sources.

On this basis, the m script that drives the test process is compiled in MATLAB according to Figure 3, where the voltage and current data used to calculate the port impedance are obtained from the data derived from the "simout" module.

The present invention calculates the equivalent impedance of each port by means of the method of "pressurizing current flow" in the circuit principle. The present invention effectively distinguishes and locates each terminal and port of the circuit under test. The present invention realizes electrical connection between the independent voltage source Vs for measuring circuit port impedance and the port under test; the present invention enumerates all ports to be tested to form a test sequence, on the one hand, it is convenient for subsequent automatic switching of test ports; Check the test items to avoid omissions. After completing the impedance measurement of a certain port, the present invention automatically measures the impedance of the next port until the test of all ports is completed. The invention monitors the measured value of port impedance in real time, and obtains its dynamic change process. In the present invention, when there are capacitive and inductive elements in the circuit under test, the impedance value measured in the dynamic process of the circuit is discarded, and the impedance value measured after the circuit reaches a steady state is used as the port impedance, which is beneficial to ensure that the port impedance can be measured for multiple times. consistency in. The present invention avoids that the simulation test time for a certain port is too long, and when the time exceeds an acceptable limit, the continuous testing of the port is stopped, thereby ensuring that the time used for completing the test sequence is controllable.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can use the methods and technical contents disclosed above to improve the present invention without departing from the spirit and scope of the present invention. The technical solutions are subject to possible changes and modifications. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention belong to the technical solutions of the present invention. protected range.

Claims (6)

1. a port impedance automatic simulation test method, is characterized in that, described method comprises the steps: Step 1: Set all active devices in the circuit under test to zero; Step 2: Assign a unique and fixed network identification number to each terminal in the circuit under test in turn; Step 3: Use the two terminal network labels in the circuit under test to represent a port, and formulate the port impedance test sequence; Step 4: Add an independent voltage source Vs specially used to measure the impedance of the circuit port, and assign network identification numbers Ni and Nj to the positive and negative terminals of the independent voltage source, so that (Ni, Nj)=Tu, where u represents the current The serial number of the port to be tested; Step 5: Record the port voltage Ui,j and the port current Ii,j of the independent voltage source Vs in real time, and calculate the equivalent impedance Zi,j of the port composed of Ni and Nj terminals in the circuit under test in real time; Step 6: Determine in real time whether the value of the equivalent impedance Zi,j of the port composed of the Ni and Nj terminals in the circuit under test satisfies the convergence condition; If the equivalent impedance Zi,j has not converged, go back to step 5, and if the equivalent impedance Zi,j has converged, go to step 7; wherein, in step 6, the convergence condition is: when the rate of change of Zi,j is less than the predetermined When the constant δ or the simulation time is greater than or equal to the preset time T0, it is considered that Zi, j has converged, otherwise, it is considered that it has not converged; Step 7: record the Zi,j calculated at the current moment as the equivalent impedance of the tested port corresponding to the impedance test serial number Tu of the u-th port; Step 8: Determine whether the port impedance test sequence has been executed, that is, whether u is equal to n; if u=n, it means that the execution has been completed, and the test is ended at this time; wherein, n is the total number of ports to be tested. 2. port impedance automatic simulation test method according to claim 1, is characterized in that also comprises: if u is not equal to n, then make u=u+1, change the value of independent voltage source terminal Ni, Nj, make ( Ni, Nj)=Tu. 3. The port impedance automatic simulation test method according to claim 1, wherein in step 1, all active devices in the circuit under test are set to zero, all voltage sources are short-circuited and all current sources are open-circuited. 4. The port impedance automatic simulation test method according to claim 1, wherein in step 2, the network identification number of the kth terminal is marked as Nk. 5. The port impedance automatic simulation test method according to claim 1, wherein in step 3, the port impedance test sequence is TS={T1=(Na, Nb), T2=(Nc, Nd),  … ,Tn=(Np,Nq)}; where n is the total number of ports to be tested, T1 is the impedance test serial number of the first port, Na is the network identification number of the a-th terminal, and Nb is the b-th terminal network identification number, T2 is the impedance test serial number of the second port, Nc is the network identification number of the cth terminal, Nd is the network identification number of the dth terminal, Tn is the impedance test serial number of the nth port, Np is the network identification number of the pth terminal, and Nq is the network identification number of the qth terminal. 6. port impedance automatic simulation test method according to claim 1 is characterized in that: in step 5, in the circuit under test, Ni, Nj two terminals form the equivalent impedance Zi of port, j obtains by following formula: Zi, j=Ui,j/Ii,j.

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