Behavioral Model of Pulse Frequency Modulator for SPICE Circuit Simulation

Abstract

The present invention relates to the fields of SPICE behavior model establishment, power electronic circuit design and closed-loop control simulation, and in particular to a behavior model of a pulse frequency modulator suitable for SPICE circuit simulation, wherein the model uses the expression function in the SPICE program to establish a pulse frequency modulator to simulate the pulse frequency modulation behavior model, and the model includes a first modulation signal circuit, a second modulation signal circuit, a third modulation signal circuit, a first comparator and a second comparator. In the present invention, two voltage signals are input to the voltage input end of the voltage-controlled voltage source, one is a voltage signal equal to the control frequency of the input pulse frequency modulator, and the other is a voltage signal equal to the dead zone time of the input pulse frequency modulator, so that the frequency output by the behavior model is adjustable and contains dead time.

Description

Technical Field

[0001] The invention relates to the technical fields of SPICE behavior model establishment, power electronic circuit design and closed-loop control simulation, and in particular to a behavior model of a pulse frequency modulator suitable for SPICE circuit simulation, which is used to realize SPICE circuit closed-loop control simulation of a power electronic converter. Background Art

[0002] Pulse frequency modulation algorithm is widely used in the control of power electronic resonant converters such as LLC and LCC, and is used to adjust the gain of resonant converters. When designing the resonant parameters of resonant converters, the fundamental wave approximation method is generally used to design the resonant converter parameters under the premise of meeting the gain and soft switching requirements. However, the traditional fundamental wave approximation method only has a high accuracy near the resonant frequency. When the switching frequency deviates from the resonant frequency, the fundamental wave approximation method cannot calculate the accurate gain of the resonant converter. Therefore, the current industry needs a method that can realize closed-loop simulation of resonant converters. Through accurate time domain simulation, the gain change of the resonant converter under different working conditions and resonant parameters can be obtained, so as to obtain the correct resonant parameter design.

[0003] In order to realize the closed-loop control simulation of the resonant converter, a behavior model of the pulse frequency modulator that can be used for SPICE circuit simulation is urgently needed. However, there is currently no behavior model of the pulse frequency modulator that can be used for SPICE circuit simulation. The present invention proposes a behavior model of the pulse frequency modulator with adjustable output frequency and dead time, which is used for SPICE closed-loop control simulation of power electronic resonant converters such as resonant converters. Summary of the invention

[0004] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures specifically pointed out in the description, claims and other drawings of the description.

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a behavioral model of a pulse frequency modulator suitable for SPICE circuit simulation. The output frequency of the behavioral model is adjustable and contains dead time, and is used for SPICE circuit closed-loop control simulation of power electronic converters such as resonant converters.

[0006] To achieve the above-mentioned purpose, the technical solution of the present invention is: a behavior model of a pulse frequency modulator suitable for SPICE circuit simulation, the model uses the expression function in the SPICE program to establish a pulse frequency modulator to simulate the pulse frequency modulation behavior model, and the model includes a first modulation signal circuit, a second modulation signal circuit, a third modulation signal circuit, a first comparator and a second comparator. Among them, the first modulation signal circuit includes a first voltage-controlled voltage source, two first voltage input terminals, and two first voltage output terminals, the two first voltage input terminals are connected to the input terminal of the first voltage-controlled voltage source, the two first voltage output terminals are connected to the output terminal of the first voltage-controlled voltage source, one of the first voltage output terminals is connected to the first comparator, and the other first voltage output terminal is grounded; the second modulation signal circuit includes a second voltage-controlled voltage source, two second voltage input terminals, and two second voltage output terminals, the two second voltage input terminals are connected to the input terminal of the second voltage-controlled voltage source The second voltage output terminals are connected to the output terminal of the second voltage-controlled voltage source, one of the second voltage output terminals is connected to the first comparator and the second comparator, and the other of the second voltage output terminals is grounded; the third modulation signal circuit includes a third voltage-controlled voltage source, two third voltage input terminals, and two third voltage output terminals, the two third voltage input terminals are connected to the input terminal of the third voltage-controlled voltage source, the two third voltage output terminals are connected to the output terminal of the third voltage-controlled voltage source, one of the third voltage output terminals is connected to the second comparator, and the other of the third voltage output terminals is grounded.

[0007] Preferably, the voltage signals input to the first voltage input terminal, the second voltage input terminal, and the second voltage input terminal are all first voltage signals and second voltage signals, the first voltage signal is a voltage signal equal to the control frequency of the input pulse frequency modulator, and the second voltage signal is a voltage signal equal to the dead time of the input pulse frequency modulator.

[0008] Preferably, the first voltage-controlled voltage source is used to generate a first modulation signal for an output pulse, the second voltage-controlled voltage source is used to generate a second modulation signal for an output pulse, and the third voltage-controlled voltage source is used to generate a third modulation signal for an output pulse.

[0009] Preferably, the second modulation signal is a triangular carrier modulation signal.

[0010] Preferably, the calculation formula of the triangular carrier modulation signal is:

[0011]

[0012] In the above formula, function abs() is the absolute value function, time is the SPICE simulation time, V f is the first voltage signal, t dt is the dead time.

[0013] Preferably, the calculation formula of the first modulation signal is:

[0014]

[0015] In the above formula, V f is the first voltage signal, V dt is the second voltage signal.

[0016] Preferably, the calculation formula of the second modulation signal is:

[0017]

[0018] In the above formula, V f is the first voltage signal, V dt is the second voltage signal.

[0019] Preferably, the first modulation signal and the second modulation signal are processed by the first comparator to generate a first pulse signal; the third modulation signal and the second modulation signal are processed by the second comparator to generate a second pulse signal.

[0020] Preferably, the first pulse signal and the second pulse signal are complementary.

[0021] Preferably, the pulse period of the first pulse signal and the second pulse signal are both the sum of the reciprocal of the input control frequency period and twice the dead time.

[0022] By adopting the above technical solution, the beneficial effects of the present invention are:

[0023] 1. In the present invention, two voltage signals are input to the voltage input end of the voltage-controlled voltage source, one is a voltage signal equal to the control frequency of the input pulse frequency modulator, and the other is a voltage signal equal to the dead time of the input pulse frequency modulator, so that the frequency output by the behavioral model is adjustable and contains dead time.

[0024] 2. The present invention is provided with three modulation signals, one is a triangular carrier signal adjusted by the input control frequency and the dead time, and the other two are modulation signals controlled by the input control frequency and the dead time. The two modulation signals are compared and analyzed with the triangular carrier signal respectively, so as to output two complementary pulse signals, and finally obtain the pulse modulator behavior model.

[0025] 3. The present invention has a simple structure, fast simulation speed and high simulation accuracy.

[0026] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure.

[0027] Undoubtedly, these and other objects of the present invention will become more apparent after the following detailed description of the preferred embodiment described with reference to various figures and drawings.

[0028] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, one or several preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation of the present invention.

[0030] In the drawings, the same reference numerals are used for the same components and the drawings are schematic and not necessarily drawn to scale.

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only one or several embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on such drawings without paying creative work.

[0032] Figure 1 A schematic diagram of a behavioral model of a pulse frequency modulator suitable for SPICE circuit simulation;

[0033] Figure 2 A signal diagram of a behavioral model of a pulse frequency modulator suitable for SPICE circuit simulation. DETAILED DESCRIPTION

[0034] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as there is no conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0035] Meanwhile, in the following description, many specific details are set forth for the purpose of explanation to provide a thorough understanding of the embodiments of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the specific details or the specific manner described herein.

[0036] This embodiment provides a behavioral model of a pulse frequency modulator suitable for SPICE circuit simulation. The model uses the expression function in the SPICE program to establish a pulse frequency modulator to simulate the pulse frequency modulation behavioral model. The model includes a first modulation signal circuit, a second modulation signal circuit, a third modulation signal circuit, a first comparator Comp1 and a second comparator Comp2.

[0037] The first modulation signal circuit includes a first voltage-controlled voltage source VCVS1, two first voltage input terminals, and two first voltage output terminals. The two first voltage input terminals are both connected to the input terminal of the first voltage-controlled voltage source VCVS1, the two first voltage output terminals are both connected to the output terminal of the first voltage-controlled voltage source VCVS1, one of the first voltage output terminals is connected to the first comparator Comp1, and the other first voltage output terminal is grounded.

[0038] The second modulation signal circuit includes a second voltage-controlled voltage source VCVS2, two second voltage input terminals, and two second voltage output terminals. The two second voltage input terminals are both connected to the input terminal of the second voltage-controlled voltage source VCVS2, the two second voltage output terminals are both connected to the output terminal of the second voltage-controlled voltage source VCVS2, one of the second voltage output terminals is connected to the first comparator Comp1 and the second comparator Comp2, and the other second voltage output terminal is grounded.

[0039] The third modulation signal circuit includes a third voltage-controlled voltage source VCVS3, two third voltage input terminals, and two third voltage output terminals. The two third voltage input terminals are both connected to the input terminal of the third voltage-controlled voltage source VCVS3, the two third voltage output terminals are both connected to the output terminal of the third voltage-controlled voltage source VCVS3, one of the third voltage output terminals is connected to the second comparator Comp2, and the other third voltage output terminal is grounded.

[0040] The first voltage input terminal, the second voltage input terminal, and the voltage signal input by the second voltage input terminal are all the first voltage signal V f and the second voltage signal V dt , the first voltage signal V f is the control frequency f of the input pulse frequency modulator s The second voltage signal V dt is the dead time t of the input pulse frequency modulator dt Equivalent voltage signal.

[0041] The first voltage-controlled voltage source VCVS1 is used to generate a first modulation signal V of the output pulse. mod1 The second voltage-controlled voltage source VCVS2 is used to generate a second modulation signal V of the output pulse swThe third voltage-controlled voltage source VCVS3 is used to generate a third modulation signal V of the output pulse. mod2 .

[0042] The second modulation signal V sw is the input controlled frequency f s and dead time t dt The adjusted triangular carrier modulation signal V sw , the triangular carrier modulated signal V sw The calculation formula is

[0043]

[0044] In the above formula, function abs() is the absolute value function, time is the SPICE simulation time, V f is the first voltage signal, t dt is the dead time.

[0045] The first modulation signal V mod1 is controlled by the input frequency f s and dead time t dt The calculation formula is:

[0046]

[0047] In the above formula, V f is the first voltage signal, V dt is the second voltage signal.

[0048] The second modulation signal V mod2 is controlled by the input frequency f s and dead time t dt The calculation formula is:

[0049]

[0050] In the above formula, V f is the first voltage signal, V dt is the second voltage signal.

[0051] The first modulation signal V mod1 With the second modulation signal V sw After being processed by the first comparator Comp1, a first pulse signal PWM1 is generated; the third modulation signal V mod2 With the second modulation signal V sw After being processed by the second comparator Comp2, a second pulse signal PWM2 is generated.

[0052] The first pulse signal PWM1 and the second pulse signal PWM2 are complementary.

[0053] The pulse periods of the first pulse signal PWM1 and the second pulse signal PWM2 are both input control frequency f s The reciprocal of the period and twice the dead time t dt sum.

[0054] The working principle of this embodiment:

[0055] Input V at the two voltage input terminals of the first voltage-controlled voltage source respectively. f and V dt (V f and V dt are respectively the control frequency f of the input pulse frequency modulator s and dead time t dt The first voltage-controlled voltage source generates a first modulation signal V mod1 , the first modulation signal V mod1 Outputted from a voltage output terminal of the first voltage-controlled voltage source and flowing into the first comparator Comp1;

[0056] Input V at the two voltage input terminals of the second voltage-controlled voltage source respectively. f and V dt (V f and V dt are respectively the control frequency f of the input pulse frequency modulator s and dead time t dt The voltage signal of the same value is regulated and controlled by the second voltage-controlled voltage source to generate a second modulation signal V sw (ie, the triangular carrier signal V sw ), the second modulation signal V sw The voltage is output from a voltage output terminal of the second voltage-controlled voltage source and flows into the first comparator Comp1 and the second comparator Comp2;

[0057] Input V at the two voltage input terminals of the third voltage-controlled voltage source respectively. f and V dt (V f and V dt are respectively the control frequency f of the input pulse frequency modulator s and dead time t dt The voltage signal of the same value) is controlled by the second voltage-controlled voltage source to generate a third modulation signal V mod2 , the third modulation signal V mod2 Outputted from a voltage output terminal of the third voltage-controlled voltage source and flowing into the second comparator Comp2;

[0058] The first modulation signal V mod1 With the triangular carrier signal V swIn the first comparator Comp1, after comparison and analysis, the first pulse signal PWM1 and the second modulation signal V mod2 With the triangular carrier signal V sw In the second comparator Comp2, after comparison and analysis, the second pulse signal PWM2 is output. The first pulse signal PWM1 and the second pulse signal PWM2 complement each other to form a behavioral model of the pulse frequency modulator. The output frequency of the behavioral model is adjustable and contains dead time, which is used for SPICE circuit closed-loop control simulation of power electronic converters such as resonant converters.

[0059] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM).

Claims

1. A behavioral model of a pulse frequency modulator suitable for SPICE circuit simulation, characterized in that: The model uses the expression function in the SPICE program to establish a pulse frequency modulator to simulate the pulse frequency modulation behavior model. The model includes a first modulation signal circuit, a second modulation signal circuit, a third modulation signal circuit, a first comparator and a second comparator; wherein, The first modulation signal circuit comprises a first voltage-controlled voltage source, two first voltage input terminals, and two first voltage output terminals, wherein the two first voltage input terminals are both connected to the input terminal of the first voltage-controlled voltage source, the two first voltage output terminals are both connected to the output terminal of the first voltage-controlled voltage source, one of the first voltage output terminals is connected to the first comparator, and the other of the first voltage output terminals is grounded; The second modulation signal circuit comprises a second voltage-controlled voltage source, two second voltage input terminals, and two second voltage output terminals, wherein the two second voltage input terminals are both connected to the input terminal of the second voltage-controlled voltage source, the two second voltage output terminals are both connected to the output terminal of the second voltage-controlled voltage source, one of the second voltage output terminals is connected to the first comparator and the second comparator, and the other second voltage output terminal is grounded; The third modulation signal circuit comprises a third voltage-controlled voltage source, two third voltage input terminals, and two third voltage output terminals, wherein the two third voltage input terminals are both connected to the input terminal of the third voltage-controlled voltage source, the two third voltage output terminals are both connected to the output terminal of the third voltage-controlled voltage source, one of the third voltage output terminals is connected to the second comparator, and the other of the third voltage output terminals is grounded; The first voltage-controlled voltage source is used to generate a first modulation signal for outputting pulses, the second voltage-controlled voltage source is used to generate a second modulation signal for outputting pulses, and the third voltage-controlled voltage source is used to generate a third modulation signal for outputting pulses, wherein the second modulation signal is a triangular carrier modulation signal; The calculation formula of the triangular carrier modulation signal is: In the above formula, function abs() is the absolute value function, time is the SPICE simulation time, V f is the first voltage signal, t dt is the dead time; The calculation formula of the first modulation signal is: In the above formula, V f is the first voltage signal, V dt is a second voltage signal; The calculation formula of the second modulation signal is: In the above formula, V f is the first voltage signal, V dt is the second voltage signal.

2. The behavioral model of a pulse frequency modulator suitable for SPICE circuit simulation according to claim 1, characterized in that: The voltage signals input to the first voltage input terminal, the second voltage input terminal, and the second voltage input terminal are all first voltage signals and second voltage signals. The first voltage signal is a voltage signal with a value equal to the control frequency of the input pulse frequency modulator, and the second voltage signal is a voltage signal with a value equal to the dead time of the input pulse frequency modulator.

3. The behavioral model of a pulse frequency modulator suitable for SPICE circuit simulation according to claim 1, characterized in that: After the first comparator processes the first modulation signal and the second modulation signal, a first pulse signal is generated; after the second comparator processes the third modulation signal and the second modulation signal, a second pulse signal is generated.

4. The behavioral model of a pulse frequency modulator suitable for SPICE circuit simulation according to claim 3, characterized in that: The first pulse signal and the second pulse signal are complementary.

5. The behavioral model of a pulse frequency modulator suitable for SPICE circuit simulation according to claim 3, characterized in that: The pulse period of the first pulse signal and the second pulse signal are both the sum of the reciprocal of the input control frequency period and twice the dead time.

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