CN111581799B - Modeling method of power electronic converter with coupled inductor and charge pump unit - Google Patents

Abstract

The invention discloses a modeling method of a power electronic converter containing a coupling inductor and a charge pump unit, which comprises a modeling module of a charge pump CP unit and a method for adding the charge pump CP unit module on the basis of a general TIS nonlinear modeling module to obtain a TIS-CP nonlinear modeling module. The modeling of a complex nonlinear part including the charge pump unit, a part of inductive elements and a switching device in the hybrid coupling inductance high-gain topology containing the charge pump unit can be completed in advance through the TIS-CP modeling module, and on the basis, a linear network state equation outside the equivalent TIS-CP module is only needed to be established and substituted into a large signal model, a steady state model and a small signal model of the equivalent TIS-CP modeling module, so that the large signal model, the steady state model and the small signal model of the target power electronic converter can be obtained. The invention can greatly reduce the workload of a user for modeling the hybrid coupling inductor high-gain topology containing the charge pump unit and improve the efficiency of modeling analysis.

Description

Modeling Method for Power Electronic Converter with Coupled Inductor and Charge Pump Unit

technical field

The invention relates to modeling technology of a power electronic converter, in particular to a modeling method of a power electronic converter including a coupling inductor and a charge pump unit.

Background technique

The modeling of power electronic converter is the basis of its design and analysis. Since the nonlinear components contained in the circuit topology of the power electronic converter are strongly nonlinear systems, it is difficult to solve them mathematically, and the classical closed-loop design method cannot be used. Therefore, it is first necessary to model the switching circuit linearly (small signal model). Simpler high-turn-ratio topologies can be modeled using the traditional average switch model method. The relatively complex ones can be modeled by state-space averaging (SSA). In addition, the switching signal flow graph nonlinear modeling method (SFG) retains the advantages of clear physical meaning and easy calculation of equational expression. However, with the improvement of the working state and order of the circuit, the state matrix equation representing the topological circuit will be correspondingly difficult to write, which brings difficulties to the topology research. In recent years, power electronic converters have mostly used winding inductive components, switched capacitors/charge pump units, etc. can further increase the gain while achieving excellent performance such as zero ripple and soft switching, but at the same time introduce complex work such as quasi-resonance state, which brings more challenges to the modeling and analysis of power electronic converters.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a modeling method of a power electronic converter including a coupled inductor and a charge pump unit.

The technical solution for realizing the object of the present invention is: a modeling method of a power electronic converter containing a coupled inductor and a charge pump unit, comprising the following steps:

Step 1. Construct the CP unit of the load pump and the TIS modeling module, and determine the models of the CP unit of the load pump and the general TIS modeling module, including steady-state model, large-signal model and small-signal model;

Step 2. Build an equivalent TIS-CP modeling module, and determine the large-signal model, steady-state model and small-signal model of the equivalent TIS-CP modeling module according to the connection mode of the charge pump CP unit and the general TIS module;

Step 3. Determine the external linear network of the equivalent TIS-CP modeling module according to the topology of the target power electronic converter and the equivalent TIS-CP modeling module;

Step 4. Determine the state equation of the external linear network of the equivalent TIS-CP module of the target power electronic converter and the internal parameters of the equivalent TIS-CP module of the target power electronic converter, including the effective turns ratio and the excitation inductance of the general coupling inductor;

Step 5. Substitute the external linear network state equation of the equivalent TIS-CP module of the target power electronic converter and the internal parameters of the equivalent TIS-CP module of the target power electronic converter into each model of the equivalent TIS-CP module established in step 2 In , the target power electronic converter model to be modeled is obtained.

Compared with the prior art, the present invention has the remarkable advantage that the charge pump unit in the hybrid coupled inductor high-gain topology containing the charge pump unit is modeled in advance, and embedded in a general TIS modeling module to generate a TIS - The CP modeling module uniformly expresses the nonlinear part of the target topology, which greatly reduces the difficulty of modeling for users and improves the efficiency of modeling and analysis.

Description of drawings

Figure 1 is a schematic diagram of an equivalent circuit of a switching power supply including a general TIS module.

Figure 2 is a large signal model diagram of the general TIS modeling module.

Figure 3 is a steady-state model diagram of the general TIS modeling module.

Fig. 4 is a small signal model diagram of the general TIS modeling module.

Fig. 5 is a schematic diagram of the charge pump CP unit and the general TIS modeling module of the TI-CP-Boost power electronic converter.

Figure 6 is a small signal model diagram of the charge pump CP unit.

Figure 7 is a black-box representation of an equivalent TIS-CP module.

Fig. 8 is a small signal model diagram of the charge pump CP unit of the TI-CP-Boost power electronic converter and its external branches.

Fig. 9 is a schematic diagram of an equivalent TIS-CP module of a TI-CP-Boost power electronic converter.

Figure 10 is a large signal model diagram of the TI-CP-Boost power electronic converter.

Figure 11 is a steady-state model diagram of the TI-CP-Boost power electronic converter.

Figure 12 is a small signal model diagram of the TI-CP-Boost power electronic converter.

Fig. 13 is a comparison chart of calculation results and simulation results of the small signal transfer function model from control to output of the TI-CP-Boost power electronic converter.

Detailed ways

The solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The modeling method of the power electronic converter containing coupled inductors and charge pump units in the present invention first constructs the modeling module of the charge pump CP unit, and then adds the charge pump CP unit to the original general TIS modeling module to form an equivalent TIS- The CP modeling module enables it to be applied to the modeling of power electronic converters with coupled inductors and charge pump units. A modeling method for a power electronic converter with a coupled inductor and a charge pump unit, specifically including the following steps:

Step 1. Construct the CP unit of the load pump and the TIS modeling module, and determine the models of the CP unit of the load pump and the general TIS modeling module, including steady-state model, large-signal model and small-signal model;

Figure 1 shows an example of a general-purpose TIS modeling module in a switching power supply, and its three terminals can be partially or fully used to connect external linear circuits. The general TIS modeling module includes a general coupled inductor primary winding (N ₁₀ ), a general coupled inductor secondary winding (N ₂₀ ), a general TIS module excitation inductance (L _m ), and a pair of PWM switches working in a complementary mode , that is, the active switch (K(d)) and the complementary switch (K(d′)), as well as terminals No. 1, No. 2, and No. 0. One end of the active switch (K(d)) is connected to No. 1 terminal, and the other end is connected to one end of the magnetizing inductance (L _m ) of the universally coupled inductor and one end of the primary winding (N ₁₀ ) of the universally coupled inductor, and the other end of the magnetizing inductance (L _m ) of the universally coupled inductor is connected to terminal 0 and The other end of the primary winding (N ₁₀ ) of the universally coupled inductor, one end of the secondary winding (N ₂₀ ) of the universally coupled inductor is connected to one end of the complementary switch (K(d′)), and the complementary switch (K(d′) ) to connect the other end to Terminal 2. According to the above characteristics, it is compared with the target power electronic converter to determine the interface terminal position of the general TIS modeling module in the target power electronic converter to be modeled.

所述励磁电感电流大信号节点o i_Lm到一号端子电流大信号节点o i₁的增益为d，所述励磁电感电流大信号节点o i_Lm到二号端子电流大信号节点o i₂的增益为-ad′，所书一号端子电流大信号节点o i₁到零号端子电流大信号节点o i₀的增益为1，所述二号端子电流大信号节点o i₂到零号端子电流大信号节点o i₀的增益为1。特别的，上述各个节点之间的支路增益中，d为目标电力电子变换器占空比的大信号参数，d′＝(1-d)为目标电力电子变换器主开关断开的时间段的大信号参数，a为通用TIS模块的有效匝数比，r为目标电力电子变换器耦合电感寄生电阻,Lm为目标电力电子变换器的励磁电感。The switching signal flow diagram of the large signal model of the general TIS modeling module is shown in Figure 2, including the voltage large signal node ov1 of the _first terminal, the large voltage node ov2 of the _second terminal, and the large signal node ov of the zero terminal ₀ , no.1 terminal current large signal node oi ₁ , no.2 terminal current large signal node oi ₂ , zero terminal current large signal node oi ₀ , exciting inductor voltage large signal node ov _Lm , exciting inductor current large signal node oi _Lm , A zero terminal voltage large signal node ov ₁₀ , a zero terminal voltage large signal node ov ₂₀ , the gain from the first terminal voltage large signal node ov ₁ to a zero terminal voltage large signal node ov ₁₀ is d, the zero The gain of terminal voltage large signal node ov ₀ to zero terminal voltage large signal node ov ₁₀ is -1, and the gain of the zero terminal voltage large signal node ov ₀ to twenty terminal voltage large signal node ov ₂₀ is -1, so The gain from the large signal node ov ₁₀ of the zero terminal voltage to the large signal node ov _Lm of the excitation inductance voltage is d, and the gain from the large signal node ov ₂₀ of the zero terminal voltage to the large signal node ov _Lm of the excitation inductance voltage is a(1 -d), the gain from the excitation inductor voltage large signal node ov _Lm to the excitation inductor current large signal node oi _Lm is

The gain from the excitation inductor current large signal node oi _Lm to the No. 1 terminal current large signal node oi ₁ is d, and the gain from the excitation inductor current large signal node oi _Lm to the No. 2 terminal current large signal node oi ₂ is -ad ′, the gain from the No. 1 terminal current large signal node oi ₁ to the No. 0 terminal current large signal node oi ₀ is 1, and the gain from the No. 2 terminal current large signal node oi ₂ to the No. 0 terminal current large signal node oi ₀ The gain is 1. In particular, in the branch gain between the above nodes, d is the large signal parameter of the duty cycle of the target power electronic converter, and d'=(1-d) is the time period when the main switch of the target power electronic converter is off , a is the effective turns ratio of the general TIS module, r is the parasitic resistance of the coupling inductance of the target power electronic converter, and Lm is the excitation inductance of the target power electronic converter.

The large-signal model of the general TIS module shown in Figure 2 can also be expressed by a system of equations composed of large-signal state variables of the general TIS module as follows:

Among them, the large voltage signal v ₁ of terminal 1, the large voltage signal v ₂ of terminal 2, the large voltage signal v ₀ of terminal 0, the large current signal i ₁ of terminal 1, the large current signal i ₂ of terminal 2, and the large current signal of terminal 0 Current large signal i ₀ , excitation inductance voltage large signal v _Lm , excitation inductance current large signal i _Lm , large signal parameter d of duty cycle of target power electronic converter, effective turns ratio a of general TIS module, target power electronic conversion The parasitic resistance r of the coupled inductor, and the excitation inductance Lm of the target power electronic converter.

所述励磁电感电流节点o I_Lm到一号端子电流节点I₁的增益为D，所述励磁电感电流节点o I_Lm到二号端子电流节点o I₂的增益为-aD′，所书一号端子电流节点o I₁到零号端子电流节点o I₀的增益为1，所述二号端子电流节点o I₂到零号端子电流节点o I₀的增益为1。特别的，上述各个节点之间的支路增益中，D为目标电力电子变换器占空比的稳态参数，D′＝(1-D)为目标电力电子变换器主开关断开的时间段的稳态参数，a为通用TIS模块的有效匝数比，r为目标电力电子变换器耦合电感寄生电阻。The general TIS modeling module steady-state model switch signal flow diagram is shown in Figure 3, including the first terminal voltage node o V ₁ , the second terminal voltage node o V ₂ , the zero terminal voltage node o V ₀ , and the first terminal voltage node o V 1 . Terminal current node o I ₁ , No. 2 terminal current node o I ₂ , No. 0 terminal current node o I ₀ , auxiliary node o 1, excitation inductance voltage node o V _Lm , excitation inductance current node o I _Lm , the No. 1 The gain from the terminal voltage node o V ₁ to the excitation inductance voltage node o V _Lm is D, and the gain from the zero terminal voltage node o V ₀ to the excitation inductance voltage node o V _Lm is -(D+aD′), the The gain from the zero terminal voltage node o V ₀ to the auxiliary node o 1 is -a, the gain from the second terminal voltage node o V ₂ to the auxiliary node o 1 is a, and the second terminal voltage node o V ₂ to The gain of the excitation inductance voltage node o V _Lm is aD′, and the gain from the excitation inductance voltage node o V _Lm to the excitation inductance current node o I _Lm is

The gain of the excitation inductance current node o I _Lm to the No. 1 terminal current node I ₁ is D, and the gain of the excitation inductance current node o I _Lm to the No. 2 terminal current node o I ₂ is -aD′. The gain from the current node o I ₁ of the No. 1 terminal to the current node o I ₀ of the No. 0 terminal is 1, and the gain from the current node o I ₂ of the No. 2 terminal to the current node o I ₀ of the No. 0 terminal is 1. In particular, among the branch gains between the above nodes, D is the steady-state parameter of the duty cycle of the target power electronic converter, and D'=(1-D) is the time period when the main switch of the target power electronic converter is turned off The steady-state parameters of , a is the effective turns ratio of the general TIS module, and r is the parasitic resistance of the coupling inductor of the target power electronic converter.

The steady-state model of the general TIS module shown in Figure 3 can also be expressed by a system of equations composed of the steady-state state variables of the general TIS module as follows:

Among them, the exciting inductor current V _Lm , the exciting inductor current I _Lm , the voltage of the first terminal V ₁ , the voltage of the second terminal V ₂ , the voltage of the zero terminal V ₀ , the current of the first terminal I ₁ , the current of the second terminal I ₂ , zero No. terminal current I ₀ , the steady-state parameter D of the duty cycle of the target power electronic converter, the effective turns ratio a of the general TIS module, and the parasitic resistance r of the coupling inductor of the target power electronic converter.

二号端子电压小信号节点

零号端子电压小信号节点

一号端子电流小信号节点

二号端子电流小信号节点

零号端子电流小信号节点

励磁电感电压小信号节点

励磁电感电流小信号节点

占空比小信号节点

所述一号端子电压小信号节点

到励磁电感电压小信号节点

的增益为D，所述零号端子电压小信号节点

到励磁电感电压小信号节点

的增益为-(D+aD′)，所述二号端子电压小信号节点

到励磁电感电压小信号节点

的增益为aD′，所述占空比小信号节点

到励磁电感电压小信号节点

的增益为V₁+(a-1)V₀-aV₂，所述占空比小信号节点

到一号端子电流小信号节点

的增益为I_Lm，所述占空比小信号节点

到二号端子电流小信号节点

的增益为-aI_Lm，所述励磁电感电压小信号节点

到励磁电感电流小信号节点

的增益为

所述励磁电感电流小信号节点

到一号端子电流小信号节点

的增益为D，所述励磁电感电流小信号节点

到二号端子电流小信号节点

的增益为aD′，所述一号电流端子小信号节点

到零号端子电流小信号节点

的增益为1，所述二号端子电流小信号节点

到零号端子电流小信号节点

的增益为1。The general TIS modeling module small-signal model switch signal flow diagram is shown in Figure 4, including the first terminal voltage small-signal node

Terminal 2 voltage small signal node

Zero terminal voltage small signal node

Terminal 1 current small signal node

Terminal 2 current small signal node

Zero terminal current small signal node

Magnetizing Inductor Voltage Small Signal Node

Magnetizing Inductor Current Small Signal Node

Duty Cycle Small Signal Node

The No.1 terminal voltage small signal node

to the magnetizing inductor voltage small signal node

The gain of D, the zero terminal voltage small signal node

to the magnetizing inductor voltage small signal node

The gain of -(D+aD′), the second terminal voltage small signal node

to the magnetizing inductor voltage small signal node

The gain of aD′, the duty cycle small signal node

to the magnetizing inductor voltage small signal node

The gain of V ₁ +(a-1)V ₀ -aV ₂ , the duty cycle small signal node

to terminal 1 current small signal node

The gain of I _Lm , the duty cycle small-signal node

To the second terminal current small signal node

The gain of -aI _Lm , the magnetizing inductor voltage small-signal node

to magnetizing inductor current small signal node

The gain is

The magnetizing inductor current small signal node

to terminal 1 current small signal node

The gain of D, the magnetizing inductor current small signal node

To the second terminal current small signal node

The gain of aD′, the No. 1 current terminal small-signal node

to zero terminal current small signal node

with a gain of 1, the No. 2 terminal current small-signal node

to zero terminal current small signal node

The gain is 1.

The small-signal model of the general TIS module shown in Figure 4 can also be expressed by a system of equations composed of small-signal state variables of the general TIS module as follows:

二号端子电压小信号

零号端子电压小信号

一号端子电流小信号

二号端子电流小信号

零号端子电流小信号

励磁电感电压小信号

励磁电感电流小信号

目标电力电子变换器占空比的稳态参数D，通用TIS模块的有效匝数比a，目标电力电子变换器耦合电感寄生电阻r,目标电力电子变换器的励磁电感Lm，目标电力电子变换器励磁电流平均值I_Lm。Among them, the small signal state variables of the TIS module include: terminal 1 voltage small signal

Terminal 2 voltage small signal

Zero terminal voltage small signal

Terminal 1 current small signal

Terminal 2 current small signal

Zero terminal current small signal

Exciting inductor voltage small signal

Exciting inductor current small signal

The steady-state parameter D of the duty cycle of the target power electronic converter, the effective turns ratio a of the general TIS module, the parasitic resistance r of the coupling inductor of the target power electronic converter, the excitation inductance Lm of the target power electronic converter, and the target power electronic converter Excitation current average value I _Lm .

Figure 5 shows a schematic diagram of the charge pump CP unit and the general TIS modeling module in the TI-CP-Boost power electronic converter. The charge pump CP unit includes a capacitor (C _P ) and a pair of diodes, namely a charging diode (D _C ) and a discharging diode (D _O ), as well as a C terminal, an O terminal and a P terminal, and one end of the capacitor (C _P ) Connect to terminal C, the other end is connected to the cathode of charging diode (D _C ) and the anode of discharging diode (D _O ), the other end of charging diode (D _C ) is connected to terminal P, and the discharging diode (D _O ) is connected to One end is connected to terminal O. According to the above characteristics, it is compared with the target power electronic converter to determine the interface terminal position of the charge pump CP unit in the target power electronic converter to be modeled.

C端子电压节点

电荷泵电容电压节点

P端子电流节点o i_P，C端子电流节点o i_C，O端子电流节点o i_O。所述P端子电压节点

到电荷泵电容电压节点

的增益为1，所述C端子电压节点

到电荷泵电容电压节点

的增益为-1，所述电荷泵电容电压节点

到C端子电流节点o i_C的增益为sC_P，所述C端子电流节点o i_C到P端子电流节点o i_P的增益为1，所述O端子电流节点o i_O到P端子电流节点o i_P的增益为-1。由于其大信号模型和稳态模型的模型结构和小信号模型是一样的，要得到其大信号模型和稳态模型和稳态模型仅需将其中的小信号变量(如

)替换为大信号变量(如v_p)或者稳态变量(如V_p)即可，故这里仅在附图中给出其小信号模型。The switch signal flow diagram of the model of the charge pump CP unit is shown in Figure 6, including the P terminal voltage node

C terminal voltage node

Charge Pump Capacitor Voltage Node

The P terminal current node oi _P , the C terminal current node oi _C , and the O terminal current node oi _O . The P terminal voltage node

to the charge pump capacitor voltage node

with a gain of 1, the C terminal voltage node

to the charge pump capacitor voltage node

with a gain of -1, the charge pump capacitor voltage node

The gain to the C-terminal current node oi _C is sCP, the gain of the C-terminal current node oi _C to the _P -terminal current node oi _P is 1, and the gain of the O-terminal current node oi _O to the P-terminal current node oi _P is -1. Since the model structure of its large-signal model and steady-state model is the same as that of the small-signal model, to obtain its large-signal model, steady-state model and steady-state model, only the small-signal variables (such as

) can be replaced by a large-signal variable (such as v _p ) or a steady-state variable (such as V _p ), so only the small-signal model is given in the accompanying drawings.

The small-signal model of the charge pump CP unit shown in Figure 6 can also be expressed by a system of equations composed of small-signal state variables of the charge pump CP unit as follows:

C号端子电压小信号

电荷泵电容电压小信号

P端子电流小信号

C端子电流小信号

O端子电流小信号

电荷泵电容C_P。Among them, the small signal state variable of the charge pump CP unit includes: P terminal voltage small signal

C terminal voltage small signal

Charge pump capacitor voltage small signal

P terminal current small signal

C terminal current small signal

O terminal current small signal

Charge pump capacitor C _P .

Step 2. Build an equivalent TIS-CP modeling module, and determine the large-signal model, steady-state model and small-signal model of the equivalent TIS-CP modeling module according to the connection mode of the charge pump CP unit and the general TIS module;

The equivalent TIS-CP modeling module is shown in Figures 7 and 9, which contains all components of the charge pump CP unit and the general TIS modeling module, where the output diode D _O of the charge pump CP unit is multiplexed as the general TIS modeling module The complementary switch (K(d')) can lead out 4 terminals, which are terminal 0, terminal 1, terminal 2 and terminal P. Construct the equivalent TIS-CP modeling module of the target converter, that is, embed the model of the charge pump CP unit built in advance into the general TIS modeling module to obtain the target converter. This operation should be combined with the port connection mode of the charge pump CP unit and the general TIS modeling module to analyze the relationship between the P terminal current i _P in the charge pump CP unit and the 1 terminal current i ₁ and 0 terminal current i ₀ in the general TIS modeling module Influence; analyze the relationship between the C-terminal voltage v _C of the charge pump CP unit and the 1-terminal voltage v ₁ and 0-terminal voltage v ₀ in the general TIS modeling module.

Since the C terminal of the charge pump CP unit will exist inside the TIS-CP modeling module after nesting, the C terminal voltage v _C of the charge pump CP unit can be used by the 1 terminal voltage v ₁ in the general TIS modeling module and 0 terminal voltage v ₀ , the C terminal current i _C is expressed by the charge pump capacitance current i _cp , and then the C terminal can be deleted. Since the O terminal of the charge pump CP unit in the equivalent TIS-CP module and the No. 2 terminal of the general TIS modeling module are the same terminal, they can be merged, that is, unified as No. 2 terminal. According to the above analysis results, the corresponding equations in the respective models of the charge pump CP unit model and the general TIS modeling module are modified, and the large-signal model, steady-state model and small-signal model of the charge pump CP unit model and the general TIS modeling module are By combining the equations separately, the large-signal model, steady-state model and small-signal model of the equivalent TIS-CP modeling module of the target converter can be obtained.

Step 3. Determine the external linear network of the equivalent TIS-CP modeling module according to the topology of the target power electronic converter and the equivalent TIS-CP modeling module;

The external linear network of the equivalent TIS-CP module includes all components in the target power electronic converter except the components in the equivalent TIS-CP module. When determining the external linear network of the equivalent TIS-CP modeling module, compare the topology of the equivalent TIS-CP modeling module with the target power electronic converter, and determine that the equivalent TIS-CP modeling The interface position of the converter, including terminal 0, terminal 1, terminal 2 and P terminal; after determining the interface position of the equivalent TIS-CP modeling module, the equivalent TIS-CP modeling surrounded by four terminals can be obtained module, and the rest is the external linear network of the equivalent TIS-CP modeling module.

Step 4. Determine the state equation of the external linear network of the equivalent TIS-CP module of the target power electronic converter and the internal parameters of the equivalent TIS-CP module of the target power electronic converter, including the effective turns ratio and the excitation inductance of the general coupling inductor;

Assuming that the effective turns ratio is a, the magnetizing inductance of the general coupling inductor is L _m or more, and the parasitic impedance parameters are r ₁ , r ₂ and r ₀ , where r ₁ is the sum of the parasitic impedance of the No. 1 terminal branch, and r ₂ is 2 The sum of the parasitic impedance of the number terminal branch, r ₀ is the sum of the parasitic impedance of the zero terminal branch, then the calculation formula of the effective turns ratio a and the excitation inductance L _m of the general coupling inductor is:

In the formula, N ₁₀ is the number of coupling inductor turns between terminal 1 and terminal 0 of the general TIS module, and N ₂₀ is the number of coupling inductor turns between terminal 2 and terminal 0 of the general TIS module. When calculating N ₁₀ and When N is ₂₀ , if the actual winding end with the same name is connected sequentially, take '+', and if it is reversed, take '-', N ₁ is the number of turns of the primary winding of the target power electronic converter, L ₁ is the number of turns of the target power electronic converter Transformer primary winding inductance.

Step 5. Substitute the external linear network state equation of the equivalent TIS-CP module of the target power electronic converter and the internal parameters of the equivalent TIS-CP module of the target power electronic converter into each model of the equivalent TIS-CP module established in step 2 In , the target power electronic converter model to be modeled is obtained;

Step 6. Obtain the steady-state solution according to the steady-state model of the target power electronic converter, and then substitute the steady-state solution into the small-signal model of the target power electronic converter to obtain the small-signal transfer function of the power electronic converter.

Example

In order to verify the validity of the scheme of the present invention, the modeling steps of the scheme of the present invention are described in detail by taking the TI-CP-Boost power electronic converter as the modeling object.

The main parameters of the TI-CP-Boost power electronic converter shown in Figure 5 are as follows, input voltage Vg=120V, load resistance R=200Ohm, output capacitor Co=47uF, switching frequency f=50kHz, excitation inductance L ₁ = 56uH, transformer equivalent leakage inductance (secondary side) L _lk =0.56μH, transformer primary and secondary turns ratio n=0.5, charge pump capacitance Cp=1uF. The above-mentioned power electronic converter with coupled inductor and charge pump unit is modeled, and the implementation steps are as follows:

Step 1. Analyze the structure of the target power electronic converter to be modeled, and identify the general charge pump CP unit and the general TIS modeling module in the target topology.

Step 2. Analyze the connection mode between the charge pump CP unit and the general TIS module, and embed the model of the charge pump CP unit built in advance into the general TIS modeling module to obtain the equivalent TIS-CP modeling module of the target power electronic converter.

The large-signal model of the charge pump CP unit in the TI-CP-Boost power electronic converter and its external branch connected to the general TIS modeling module is shown in Figure 8. According to the branch connected between the charge pump CP unit and the general TIS modeling module, the following relationship between the variables of the two modules can be obtained:

i _0c ＝-ni _P

i _1c ＝-(n+1)i _P

i _O =i _2c

v _Lmcp ＝-a(1-d)v _cp

v _C ＝(n+1)v ₁ -nv ₀

Among them, i _0cp , i _1cp and i _2cp are the 0-terminal current component, 1-terminal current component and 2-terminal current component of the general TIS modeling module caused by the charge pump CP unit, v _Lmcp is the general TIS current component caused by the charge pump CP unit The magnetizing inductance voltage component of the TIS modeling module.

At the same time, it is considered that the terminal current has the following relationship in the general TIS modeling module:

i ₀ =i ₁ +i ₂

The large signal model equation of the charge pump CP unit and the general TIS modeling module can be modified and combined to obtain the large signal model of the equivalent TIS-CP modeling module as follows:

Step 3. Analyze the topology of the target power electronic converter to be modeled, divide the target power electronic converter into two parts: the equivalent TIS-CP modeling module and the external linear network of the equivalent TIS-CP modeling module, and construct the The target power electronic converter TIS-CP equivalent circuit composed of the switch conversion equivalent TIS-CP module and the target power electronic converter equivalent TIS-CP module external linear network is shown in Figure 9;

Step 4. Determine the state equation of the external linear network of the equivalent TIS-CP module of the target power electronic converter. According to the equivalent TIS-CP module external linear network in the TIS-CP-Boost converter, the state equation of the external linear network is obtained as follows:

where the load impedance Z _out is:

And the internal parameters of the equivalent TIS-CP module of the target power electronic converter, including the effective turns ratio a, and the excitation inductance L _m of the general coupling inductor are as follows:

In the formula, N ₁₀ is the number of coupling inductance turns between terminals 1 and 0 of the equivalent TIS-CP module of the TIS-CP-Boost power electronic converter, and N ₂₀ is the equivalent TIS-CP of the TIS-CP-Boost power electronic converter The number of coupling inductor turns between module terminals 2 and 0, N ₁ is the number of turns of the primary winding of the transformer of the TIS-CP-Boost power electronic converter, L ₁ is the number of turns of the power electronic converter modeled by the TIS-CP-Boost switch Transformer primary winding inductance.

Step 5. Substitute the external linear network state equation of the equivalent TIS-CP module of the target power electronic converter and the internal parameters of the equivalent TIS-CP module of the target power electronic converter into the steady-state model, large signal model or In the small-signal model, a steady-state model, a large-signal model or a small-signal model of the target power electronic converter to be modeled is obtained.

The large signal model of the TIS-CP-Boost power electronic converter shown in Figure 10 can also be expressed in the form of equations as follows:

The steady-state model of the TIS-CP-Boost power electronic converter shown in Figure 11 can also be expressed in the form of equations as follows:

The steady-state solution expression can be obtained from the steady-state model equation as follows:

V _cp = nV _g

The small-signal model of the TIS-CP-Boost power electronic converter shown in Figure 12 can also be expressed in the form of equations as follows:

The expression of the gain Z _out is:

Step 6. Obtain the steady-state solution according to the steady-state model of the target power electronic converter, and then substitute the steady-state solution into the small-signal model of the target power electronic converter, that is, the small-signal transfer function of the converter can be used for further analysis and calculation.

Substituting the steady-state solution obtained in step 5 into the small-signal model of the TIS-CP-Boost power electronic converter, the small-signal transfer function from control to output of the converter can be obtained as follows:

Substituting the simulation parameters in this example into the above formula, the small signal transfer function of TI-CP-Boost can be obtained as:

Figure 13 shows the comparison between the Bode diagram of the frequency domain characteristics of the TI-CP-Boost power electronic converter from control to output calculated by this modeling method and the Bode diagram of the frequency domain characteristics of control to output obtained through simulation. It can be seen that The two have a high degree of matching, and the simulation results verify the correctness of this modeling method.

Claims (8)

1. A method of modelling a power electronic converter comprising a coupled inductor and a charge pump unit, comprising the steps of:

step 1, constructing a load pump CP unit and a TIS modeling module, and determining models of the load pump CP unit and the general TIS modeling module, wherein the models comprise a steady-state model, a large signal model and a small signal model;

step 2, constructing an equivalent TIS-CP modeling module, and determining a large signal model, a steady-state model and a small signal model of the equivalent TIS-CP modeling module according to the connection mode of the CP unit of the charge pump and the general TIS module;

step 3, determining an external linear network of the equivalent TIS-CP modeling module according to the topology of the target power electronic converter and the equivalent TIS-CP modeling module;

step 4, determining a state equation of an external linear network of the equivalent TIS-CP module of the target power electronic converter and internal parameters of the equivalent TIS-CP module of the target power electronic converter, wherein the internal parameters comprise an effective turn ratio and excitation inductance of the general coupling inductance;

step 5, substituting the external linear network state equation of the equivalent TIS-CP module of the target power electronic converter and the internal parameters of the equivalent TIS-CP module of the target power electronic converter into each model of the equivalent TIS-CP module established in the step 2 to obtain a model of the target power electronic converter to be modeled;

in step 1, the constructed CP unit of the charge pump comprises a capacitor (C) _P ) And a pair of diodes, i.e. charging diodes (D) _C ) And a discharge diode (D) _O ) And a C terminal, an O terminal and a P terminal, the capacitor (C) _P ) One end is connected with the C terminal, and the other end is connected with a charging diode (D) _C ) Cathode and discharge diode (D) _O ) The charging diode (D), the anode of (C), the charging diode (D) _C ) The other end is connected with a P terminal, and the discharge diode (D) _O ) The other end is connected with an O terminal;

the large signal model of the charge pump CP unit is expressed as:

the steady state model is represented as:

the small signal model is represented as:

wherein, the voltage of the capacitor CP of the charge pump is a large signal v _cp With steady-state signal of V _cp The small signal is

The current of the charge pump capacitor CP is large signal i _cp With a steady-state signal of I _cp Small signal is

The P terminal voltage is a large signal v _P With steady-state signal V _P The small signal is

The P terminal current large signal is i _P With a steady-state signal of I _P The small signal is

The voltage of the C terminal is a large signal v _C With steady-state signal V _C The small signal is

The large current signal of the C terminal is i _C With a steady-state signal of I _C The small signal is

The large current signal of the O terminal is i _O With a steady-state signal of I _O Small signal is

The charge pump capacitance is C _P 。

2. Method for modelling a power electronic converter comprising a coupled inductor and a charge pump unit according to claim 1, characterized in that in step 1 the generic TIS modelling module is constructed comprising a generic coupled inductor primary winding (N) ₁₀ ) General coupled inductor secondary winding (N) ₂₀ ) And a general TIS module excitation inductor (L) _m ) A pair of switches of the PWM operating in complementary mode, namely an active switch (K (d)) and a complementary switch (K (d')), and a terminal No. 1, a terminal No. 2, a terminal No. 0, the active switch (K (d)) being connected at one end to the terminal No. 1 and at the other end to the magnetizing inductance (L) of the general coupling inductance _m ) And primary winding (N) of a common coupling inductor ₁₀ ) One terminal, excitation inductance (L) of the general coupling inductance _m ) The other end is connected with a No. 0 terminal and a primary winding (N) of the general coupling inductor ₁₀ ) The other end, the secondary winding (N) of the general coupling inductor ₂₀ ) One end of the complementary switch (K (d ')) is connected with one end of the complementary switch (K (d ')), and the other end of the complementary switch (K (d ')) is connected with the No. 2 terminal.

3. A method of modelling a power electronic converter including a coupled inductor and a charge pump unit according to claim 2, wherein the large signal model of the generic TIS modelling module is represented as:

the steady state model is represented as:

the small signal model is represented as:

wherein, the large signal of the No. 1 terminal voltage is v ₁ With steady-state signal V ₁ Small signal is

The large signal of No. 2 terminal voltage is v ₂ With steady-state signal of V ₂ The small signal is

Terminal voltage 0 is large signal v ₀ With steady-state signal of V ₀ Small signal is

The large current signal of the No. 1 terminal is i ₁ With a steady-state signal of I ₁ Small signal is

The large current signal of No. 2 terminal is i ₂ With a steady-state signal of I ₂ The small signal is

The large current signal of the No. 0 terminal is i ₀ With a steady-state signal of I ₀ Small signal is

The excitation inductance voltage is a large signal v _Lm With steady-state signal of V _Lm Small signal is

The excitation inductance current is large signal i _Lm With a steady-state signal of I _Lm Small signal is

The large signal parameter of the converter duty ratio is D, the steady-state signal is D, and the small signal is D

Converter operating frequency of f _s (ii) a The effective turn ratio of the general TIS module is a; the parasitic resistance of the coupling inductor of the converter is r; the excitation inductance of the converter is Lm.

4. Method for modelling a power electronic converter comprising a coupled inductor and a charge pump unit according to claim 1, characterized in that in step 2 the equivalent TIS-CP modelling module is constructed comprising all the components of the charge pump CP unit and the generic TIS modelling module, wherein the output diode (D) of the charge pump CP unit _O ) The terminal is multiplexed as a complementary switch (K (d')) of the general TIS modeling module, and 4 terminals are led out from the external terminal, namely a No. 0 terminal, a No. 1 terminal, a No. 2 terminal and a P terminal.

5. The method of claim 1, wherein the equivalent TIS-CP modeling module embeds a model of the charge pump CP unit to be constructed into the general TIS modeling module, and the C terminal voltage (v) of the charge pump CP unit is embedded in the TIS-CP modeling module because the C terminal of the charge pump CP unit is embedded in the TIS-CP modeling module _C ) Modeling the 1-terminal voltage (v) in the module with generic TIS ₁ ) And 0 terminal voltage (v) ₀ ) Indicates that the current (i) of the C terminal is applied _C ) With charge pump capacitance current (i) _cp ) Indicating that the C terminal is further deleted; since the O terminal of the charge pump CP unit in the equivalent TIS-CP module and the No. 2 terminal of the general TIS modeling module are the same terminal, the O terminal and the No. 2 terminal are combined, namely unified into the No. 2 terminal; according to the analysis result, corresponding equations in the CP unit model of the charge pump and the general TIS modeling module are modified, and the CP unit model of the charge pump and the general TIS modeling module are modeledEquations in the large signal model, the steady-state model and the small signal model of the module are respectively connected in a simultaneous mode, and the large signal model, the steady-state model and the small signal model of the equivalent TIS-CP modeling module of the target converter are obtained.

6. The modeling method of the power electronic converter with the coupling inductor and the charge pump unit according to claim 1, wherein in step 3, the equivalent TIS-CP module external linear network comprises all components of the target power electronic converter except for components in the equivalent TIS-CP module, when the equivalent TIS-CP modeling module external linear network is determined, the equivalent TIS-CP modeling module is compared with the target power electronic converter in a topological manner, and the interface position of the equivalent TIS-CP modeling module in the target power electronic converter to be modeled comprises a terminal No. 0, a terminal No. 1, a terminal No. 2 and a terminal P; and after the interface position of the equivalent TIS-CP modeling module is determined, the equivalent TIS-CP modeling module surrounded by the four terminals is obtained, and the rest part is the external linear network of the equivalent TIS-CP modeling module.

7. A method for modelling a power electronic converter comprising a coupled inductor and a charge pump unit as claimed in claim 1, wherein in step 4, the effective turn ratio a, the excitation inductance L of the common coupled inductor, and the like are determined _m The specific method comprises the following steps:

in the formula, N ₁₀ Number of coupled inductor turns, N, between terminal No. 1 and terminal No. 0 of general TIS module ₂₀ For the number of coupling inductance turns between the No. 2 terminal and the No. 0 terminal of the general TIS module, N is calculated ₁₀ And N ₂₀ In the case of direct connection, the winding takes '+' if the same-name end of the actual winding is connected, and takes '-' and N if the opposite end is connected ₁ Number of turns of primary winding of transformer for target power electronic converter, L ₁ The inductance of the primary winding of the transformer of the target power electronic converter.

8. A method of modelling a power electronic converter including a coupled inductor and a charge pump unit according to claim 1, the method further comprising the steps of:

and obtaining a steady state solution according to the steady state model of the target power electronic converter, and substituting the steady state solution into the small signal model of the target power electronic converter to obtain the small signal transfer function of the power electronic converter.

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