A three-phase dual active bridge dc converter hybrid modulation robust control method

Abstract

The application relates to a kind of three-phase dual active bridge DC converter hybrid modulation robust control methods, comprising: obtaining target voltage, primary side DC voltage and secondary side DC voltage;The target voltage is input to robust controller, and control output variable is obtained;The voltage variable ratio of three-phase dual active bridge DC converter is calculated;Control output variable and the voltage variable ratio of three-phase dual active bridge DC converter are input to hybrid modulation strategy controller, and target primary side duty ratio, target secondary side duty ratio and target primary-secondary two sides phase shift angle are obtained;Target primary side duty ratio, target secondary side duty ratio and target primary-secondary two sides phase shift angle are input to respective slow loop controller for decoupling, and primary side duty ratio control amount, secondary side duty ratio control amount and primary-secondary two sides phase shift angle control amount are obtained, and three-phase dual active bridge DC converter is controlled.The application can improve system robustness, so that the system has faster response speed, smaller steady-state error and smaller overshoot.

Description

Technical Field

[0001] This invention relates to the field of three-phase dual active bridge DC-DC converter control technology, and in particular to a hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter. Background Technology

[0002] Three-phase dual-active-bridge (3p-DAB) DC-DC converters offer advantages such as electrical isolation, high power density, automatic seamless power flow switching, and high efficiency, making them widely used in electric vehicles, DC microgrids, energy storage, aerospace, and other fields. The traditional modulation strategy for 3p-DABs is single-phase shift modulation (SPS), which is simple and easy to apply. However, when using SPS modulation, the 3p-DAB cannot achieve soft switching under low-load conditions (i.e., when the output power is far below the rated power), leading to reduced efficiency.

[0003] To broaden the soft-switching range of 3p-DABs, researchers have proposed asymmetrical duty-cycle control (ADCC) and simultaneous pulse width modulation (SPWM). ADCC and SPWM can effectively broaden the soft-switching range of 3p-DABs, especially under light load conditions, and can effectively improve the operating efficiency of 3p-DABs under light load conditions.

[0004] Combining the aforementioned SPS modulation, ADCC modulation, and SPWM modulation constitutes a hybrid modulation strategy. This strategy has three degrees of freedom for control, resulting in a large range of system parameter variations. Currently, dynamic control methods for the 3p-DAB hybrid modulation strategy include traditional PI control, hysteresis control, and model predictive control. Traditional PI control is simple and easy to apply, but due to the multiple control variables in the hybrid modulation strategy, its robustness is poor, and it is prone to oscillations at the modal critical point. Hysteresis control can solve the modal critical point oscillation problem, but due to the hysteresis width, its steady-state error and dynamic response are poor. Model predictive control requires a large amount of computation and necessitates a high-speed processor. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a hybrid modulation robust control method for a three-phase dual active bridge DC converter, which can improve the robustness of the system and make the system have a faster response speed, smaller steady-state error and smaller overshoot.

[0006] The technical solution adopted by this invention to solve its technical problem is: to provide a hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter, comprising the following steps:

[0007] Obtain the target voltage, primary-side DC voltage, and secondary-side DC voltage;

[0008] The target voltage is input into the robust controller to obtain the control output variable;

[0009] Calculate the voltage ratio of the three-phase dual active bridge DC converter based on the primary-side DC voltage and the secondary-side DC voltage;

[0010] The control output variable and the voltage turns ratio of the three-phase dual active bridge DC converter are input to the hybrid modulation strategy controller to obtain the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both the primary and secondary sides of the target.

[0011] The target primary side duty cycle, target secondary side duty cycle, and phase shift angles on both sides of the target primary and secondary sides are respectively input into their respective slow loop controllers for decoupling, to obtain the primary side duty cycle control quantity, secondary side duty cycle control quantity, and phase shift angle control quantity on both sides of the primary and secondary sides;

[0012] The three-phase dual active bridge DC converter is controlled by the primary-side duty cycle control quantity, the secondary-side duty cycle control quantity, and the phase shift angle control quantities on both the primary and secondary sides.

[0013] The step of inputting the target voltage into the robust controller to obtain the control output variable specifically includes:

[0014] The target voltage is coupled to the secondary DC voltage and input into a discrete integrator for integration tracking.

[0015] The target voltage and the output of the discrete integrator are input together into the H∞ robust control loop to obtain the control output variable.

[0016] The voltage transformation ratio of the three-phase dual active bridge DC converter is achieved through... The calculation yielded that, This refers to the voltage turns ratio of a three-phase dual active bridge DC-DC converter. For transformer turns ratio, This is the secondary DC voltage. This is the primary side DC voltage.

[0017] The hybrid modulation strategy controller adopts a hybrid modulation strategy consisting of SPS modulation strategy and asymmetric duty cycle modulation strategy. The asymmetric duty cycle modulation strategy includes: triangular current Buck modulation, triangular current Boost modulation, trapezoidal current modulation and synchronous pulse width modulation.

[0018] The hybrid modulation strategy controller includes:

[0019] The first judgment unit is used to determine whether the voltage ratio of the three-phase dual active bridge DC converter is equal to 1;

[0020] The first output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides using an SPS modulation strategy when the voltage ratio of the three-phase dual active bridge DC converter is equal to 1.

[0021] The second output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides according to the control output variable using the first hybrid modulation strategy control quantity analysis table when the voltage ratio of the three-phase dual active bridge DC converter is less than 1.

[0022] The third output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides according to the control output variable using the second hybrid modulation strategy control quantity analysis table when the voltage ratio of the three-phase dual active bridge DC converter is greater than 1.

[0023] The first hybrid modulation strategy control quantity analysis table is as follows:

[0024]

[0025] in, To control the output variables, The target primary edge duty cycle, For the target secondary duty cycle, The phase shift angles on both sides of the target primary and secondary are... This refers to the voltage turns ratio of a three-phase dual active bridge DC-DC converter. , , , , , , , .

[0026] The second hybrid modulation strategy control quantity analysis table is as follows:

[0027]

[0028] in, To control the output variables, The target primary edge duty cycle, For the target secondary duty cycle, The phase shift angles on both sides of the target primary and secondary are... This refers to the voltage turns ratio of a three-phase dual active bridge DC-DC converter. , , , , , , , .

[0029] The technical solution adopted by this invention to solve its technical problem is to provide a hybrid modulation robust control device for a three-phase dual active bridge DC-DC converter, comprising:

[0030] The acquisition module is used to acquire the target voltage, primary side DC voltage, and secondary side DC voltage.

[0031] The robust control module is used to input the target voltage into the robust controller to obtain the control output variable;

[0032] The calculation module is used to calculate the voltage ratio of the three-phase dual active bridge DC converter based on the primary side DC voltage and the secondary side DC voltage.

[0033] The hybrid modulation module is used to input the control output variable and the voltage ratio of the three-phase dual active bridge DC converter to the hybrid modulation strategy controller to obtain the target primary duty cycle, the target secondary duty cycle, and the phase shift angles of the target primary and secondary sides;

[0034] The decoupling module is used to decouple the target primary side duty cycle, the target secondary side duty cycle, and the phase shift angles on both sides of the target primary and secondary sides from their respective slow loop controllers to obtain the primary side duty cycle control quantity, the secondary side duty cycle control quantity, and the phase shift angle control quantity on both sides of the primary and secondary sides.

[0035] The control module is used to control the three-phase dual active bridge DC converter using the primary side duty cycle control quantity, the secondary side duty cycle control quantity, and the phase shift angle control quantities on both the primary and secondary sides.

[0036] The technical solution adopted by the present invention to solve its technical problem is: to provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-mentioned three-phase dual active bridge DC converter hybrid modulation robust control method.

[0037] The technical solution adopted by the present invention to solve its technical problem is: to provide a computer-readable storage medium on which a computer program is stored, wherein when the computer program is executed by a processor, the steps of the above-mentioned three-phase dual active bridge DC converter hybrid modulation robust control method are implemented.

[0038] Beneficial effects

[0039] Due to the adoption of the above technical solutions, the present invention has the following advantages and positive effects compared with the prior art: the hybrid modulation of the present invention broadens the soft switching range of the three-phase dual active bridge DC-DC converter, enabling it to have high efficiency over a wide output power range; robust control enables the three-phase dual active bridge DC-DC converter to have better anti-disturbance performance, thereby improving the system robustness and enabling the system to have faster response speed, smaller steady-state error, and smaller overshoot. Attached Figure Description

[0040] Figure 1 This is a flowchart of the hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter according to the first embodiment of the present invention;

[0041] Figure 2 This is a block diagram of the hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter according to the first embodiment of the present invention.

[0042] Figure 3 This is a circuit topology diagram of the three-phase dual active bridge DC-DC converter in the first embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of various modulation strategies of the three-phase dual active bridge DC converter in the first embodiment of the present invention, wherein (a) is SPS modulation, (b) is TCM3-Buck modulation, (c) is TCM3-Boost modulation, (d) is TZM3 modulation, and (e) is SPWM modulation.

[0044] Figure 5 This is a schematic diagram of the soft-switching range of hybrid modulation in the first embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram of the SPWM mode in the first embodiment of the present invention;

[0046] Figure 7 This is the equivalent circuit diagram of the three-phase dual active bridge DC-DC converter in the first embodiment of the present invention;

[0047] Figure 8 This is a 40V output voltage response diagram after adopting the first embodiment of the present invention;

[0048] Figure 9 This is a schematic diagram of load switching after adopting the first embodiment of the present invention;

[0049] Figure 10 This is a response diagram when the output voltage is switched from 40V to 60V after adopting the first embodiment of the present invention;

[0050] Figure 11 This is a power comparison chart showing different output powers when using the first embodiment of the present invention and other conventional methods;

[0051] Figure 12 This is a power comparison chart under different voltage turns ratios when using the first embodiment of the present invention and other conventional methods. Detailed Implementation

[0052] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0053] The first embodiment of the present invention relates to a hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter, which can be applied to, for example... Figure 3 The three-phase dual active bridge DC-DC converter shown consists of inverters on both the primary and secondary sides, a three-phase high-frequency transformer, and capacitors. The 3p-DAB hybrid modulation strategy in this embodiment comprises traditional SPS modulation and asymmetric duty cycle modulation. The asymmetric duty cycle modulation can be further divided into Triangular Current Modulation-Buck (TCM3-Buck), Triangular Current Modulation-Boost (TCM3-Boost), Trapezoidal Current Modulation (TZM3), and Simultaneous Pulse Width Modulation (SPWM). The corresponding drive waveforms and corresponding phase voltages and currents are as follows: Figure 4 As shown.

[0054] The switching frequency of the 3p-DAB is The corresponding switching cycle is The half-switching period is defined as half the switching period. The 3p-DAB hybrid modulation strategy has three control degrees of freedom: primary-side duty cycle and primary-side duty cycle. (by (Based on the baseline) Secondary duty cycle (by (Based on the original and the secondary phase shift angles) (by (Based on). To unify these three control degrees of freedom, this implementation defines the distance from the center of the primary high-level signal to the center of the secondary high-level signal as... , With half a cycle Based on the above definition, the following relationship exists:

[0055] (1-1)

[0056] In traditional SPS modulation, the duty cycle on both the primary and secondary sides is fixed at 0.5. The phase shift angle is adjusted... The output power is changed by varying the power output. To make the 3p-DAB transmission power monotonic, SPS modulation is used... The maximum value is 1 / 6. ADCC modulation adjusts the primary-side duty cycle. Secondary duty cycle Phase shift angle This changes the output power and broadens the soft-switching range of the 3p-DAB under light load conditions. The soft-switching range of the 3p-DAB after hybrid modulation is as follows: Figure 5 As shown.

[0057] Triangular current Buck modulation, steady-state voltage and current waveforms are as follows Figure 2 As shown in (b), the rising edges of the primary and secondary sides of the triangular current Buck modulation drive waveform coincide, and the phase current... exist and The duty cycle reaches zero at any given time, thus achieving soft switching on both the primary and secondary sides, either zero-voltage switching (ZVS) or zero-current switching (ZCS). Triangular current Buck modulation requires the input voltage to be greater than the output voltage. Based on these constraints and the steady-state waveform, the duty cycle of the primary side can be calculated. and secondary duty cycle Satisfy the following formula:

[0058] (1-2)

[0059] in, For 3p-DAB voltage turns ratio, , For transformer turns ratio, Primary DC voltage, This is the secondary DC voltage. The phase shift angle during Buck modulation of the triangular current. Since the sum of equations is zero, combining equations (1-1) and (1-2) yields:

[0060] (1-3)

[0061] Define power reference value as follows:

[0062] (1-4)

[0063] in, This refers to the leakage inductance of the transformer. This is the transmitted power after standardization. , This represents the actual transmitted power. The transmitted power of the triangular current Buck modulation is as follows:

[0064] (1-5)

[0065] Hybrid modulation of triangular current Buck modulation limits the primary-side duty cycle due to modulation characteristics. The range constraints are Between, secondary side duty cycle The range is Phase shift angle Based on the original side duty cycle The range of values ​​can be obtained under triangular current Buck modulation. The maximum value is ,Will Substituting the maximum value into equation (1-5), we can obtain the maximum transmission power of the triangular current Buck modulation as:

[0066] (1-6)

[0067] Triangular current boost modulation, steady-state voltage and current waveforms are as follows Figure 2 As shown in (c), the falling edges of the primary and secondary sides of the triangular current Boost modulation drive waveform coincide, and the phase current... exist and The voltage reaches zero at any given moment. Triangular current boost modulation requires the input voltage to be less than the output voltage. Based on the above constraints and the steady-state waveform, the primary-side duty cycle can be calculated. and secondary duty cycle Satisfy the following formula:

[0068] (1-7)

[0069] Substituting equation (1-7) into equation (1-1) yields:

[0070] (1-8)

[0071] The transmission power of the triangular current boost modulation is as follows:

[0072] (1-9)

[0073] Hybrid modulation of triangular current boost modulation limits the primary-side duty cycle due to modulation characteristics. The range constraints are Secondary duty cycle The range is Phase shift angle The range is Then we can obtain the triangular current boost modulation. The maximum value is Therefore, the maximum transmission power of triangular current boost modulation is:

[0074] (1-10)

[0075] Trapezoidal current modulation, steady-state voltage and current waveforms are as follows Figure 2 As shown in (d), its current waveform exhibits a trapezoidal shape, and in and The time is zero. Trapezoidal current modulation has two operating modes: buck mode and boost mode. In buck mode, based on the above constraints and steady-state waveform, the primary-side duty cycle can be obtained. Secondary duty cycle and phase shift angle Satisfy the following formula:

[0076] (1-11)

[0077] The transmission power of the trapezoidal current modulation buck mode is as follows:

[0078] (1-12)

[0079] Under hybrid modulation, the trapezoidal current is limited by the modulation characteristics, which restricts the primary-side duty cycle. The range constraints are Secondary duty cycle The range is Phase shift angle The range is Then we can obtain the trapezoidal current drop model. The range of values ​​is The transmission power range of the trapezoidal current modulation buck mode is as follows:

[0080] (1-13)

[0081] Primary-side duty cycle in boost mode Secondary duty cycle and phase shift angle Same as equation (1-11), but The range of values ​​changes as follows The transmission power range of the trapezoidal current modulation boost mode is as follows:

[0082] (1-14)

[0083] Following the trapezoidal current is synchronous pulse width modulation (SPWM). This is done to ensure a smoother transition between the trapezoidal current and SPWM modulation, maintaining power continuity during the transition and avoiding mode switching issues. Mode switching significantly reduces system reliability and efficiency. The modulation characteristic of SPWM is the primary-side duty cycle... equal to the duty cycle of the secondary side By simultaneously adjusting the duty cycle of the primary side Secondary duty cycle and phase shift angle This is used to change the transmission power. SPWM modulation has 7 modes, but this implementation only uses 2 modes, and the power expressions for these two modes are consistent. The modes are as follows: Figure 6 As shown. The power transmission expressions for SPWM Mode Ⅰ and Mode Ⅱ are:

[0084] (1-15)

[0085] When the system is in buck mode, let the maximum transmission power of the trapezoidal current modulation be equal to the transmission power of the SPWM. The critical solution of the SPWM modulation is as follows:

[0086] (1-16)

[0087] Similarly, the critical solution for SPWM modulation when the system is in boost mode can be obtained as follows:

[0088] (1-17)

[0089] Equations (1-16) and (1-17) above are critical solutions. The SPWM transmission power and the maximum transmission power of the current modulation are equal in this solution, achieving power continuity between modes. From Figure 6 It can be seen that the critical solution falls exactly on SPWM Mode Ⅰ. After that, the phase shift is kept constant, that is, the phase shift in the critical solution is kept constant, while the primary side duty cycle is increased. Secondary duty cycle The strategy completes the transition from SPWM to SPS; it is important to note that the primary-side duty cycle needs to be increased. Secondary duty cycle The time limit is subject to constraints, namely:

[0090] (1-18)

[0091] In the formula, The critical solution for phase shift in equations (1-16) and (1-17) is given by equation (1-18). The constraint in equation (1-18) will eventually bring the solution of SPWM modulation to the boundary between Mode II and Mode III. The transmission power expression of Mode III is the same as that of SPS, thus achieving power continuity at the boundary of all modes.

[0092] when At this time, the 3p-DAB operates with the highest efficiency in SPS modulation, therefore, when the output voltage reaches the condition... The 3p-DAB selects SPS modulation.

[0093] Based on the above analysis of different modulation methods under hybrid modulation, we can conclude that: the transmission power of 3p-DAB is continuous at all mode boundaries, and the primary duty cycle of the three control degrees of freedom is... Secondary duty cycle and phase shift angle Depend on Unification, transformed into a discussion To achieve dynamic control, this implementation introduces a control output variable for modulation of one degree of freedom. Table 1 below summarizes the analytical solutions of the control quantities for each mode of the hybrid modulation strategy, and the control output variables. A positive value indicates that power flows in the forward direction, while a negative value indicates that power flows in the reverse direction.

[0094] Table , Depend on The decision, taking the pressure reduction mode as an example, is... ;

[0095] (1-19)

[0096] Based on the above constraints and ensuring that the duty cycle increases linearly, the solution can be obtained as follows:

[0097] (1-20)

[0098] The derivation process is similar for the boost mode. , , .

[0099] Table 1 Analytical Solution of Control Quantities for Hybrid Modulation Strategy

[0100]

[0101] To overcome the limitations of the State-Space Averaging (SSA) method in modeling dual active bridge DC-DC converters, the Generalized State-Space Averaging (GSSA) method is applied to 3p-DAB modeling and analysis. This modeling method defines the switching functions of the switching components, performs Fourier expansion on them, and then models the leakage inductance current and output voltage.

[0102] Primary-side driving waveform It can be expressed by the following equation:

[0103] (2-1)

[0104] in, This represents the duty cycle of the original edge. The switching cycle. The Fourier expansion is:

[0105] (2-2)

[0106] in, This is the switching angular frequency. and Separate lag and ,so ,

[0107] .

[0108] secondary side driving waveform It can be expressed by the following equation:

[0109] (2-3)

[0110] in, For the secondary side duty cycle, The phase shift angle is the angle between the primary and secondary sides. The Fourier expansion is:

[0111] (2-4)

[0112] and Separate lag and ,so , .

[0113] For phase A voltage satisfy:

[0114] (2-5)

[0115] Substituting the Fourier expansion series of the driving waveform into equation (2-5) yields:

[0116] (2-6)

[0117] Similarly, the phase voltage of phase A referred to the primary side from the secondary side can be obtained. as follows:

[0118] (2-7)

[0119] The equivalent circuit of a 3p-DAB is as follows: Figure 7 As shown, the phase current and phase voltage of phase A satisfy the following relationship:

[0120] (2-8)

[0121] in, The equivalent inductance of phase A, This refers to the phase current of phase A. This is the equivalent resistance of phase A.

[0122] Substituting equations (2-6) and (2-7) into equation (2-8), we obtain... The expression is as follows:

[0123] (2-9)

[0124] in, The phase currents of phases B and C lag behind the phase current of phase A. and ,have , .

[0125] Based on the above known conditions, the current at the front end of the output capacitor can be calculated. for:

[0126] (2-10)

[0127] In formula (10) Three-phase transformer parameter balance ,have:

[0128] (2-11)

[0129] In the formula Assume the 3p-DAB input is a voltage source with a constant voltage value. In equation (2-11) Therefore, the output voltage across the first-order GSSA capacitor can be expressed as:

[0130] (2-12)

[0131] In the formula For load resistance, For output capacitor, It is the average output voltage when the system reaches steady state. Equation (2-12) is the steady-state equation. The transfer function to the output voltage, with a small disturbance introduced. and ,satisfy:

[0132] (2-13)

[0133] For the steady-state value, substituting equation (2-13) into equation (2-12) finally yields:

[0134] (2-14)

[0135] The state equations of the LPV system are expressed as follows:

[0136] (2-15)

[0137] In the formula For state variables, To control the input, It is system output. It is about The coefficient matrix.

[0138] Multicellular models are convex combinations of finite vertex matrices, with time-varying parameter sequences. Limited by space In, that is This means the system has There are several variable parameters. vertices { }.right The convex decomposition is as follows:

[0139] (2-16)

[0140] The coefficient matrix of equation (2-15) is as follows:

[0141] (2-17)

[0142] The coefficient matrix can take values ​​in the following matrix polytopes:

[0143] (2-18)

[0144] Equation (2-18) can be expressed as:

[0145] (2-19)

[0146] To design a robust controller for a three-phase dual active bridge DC-DC converter, the generalized LPV system state equations need to be introduced as follows:

[0147] (2-20)

[0148] In the formula etc. are all about The coefficient matrix, For system interference, To evaluate the output.

[0149] The output voltage equation of the three-phase dual active bridge DC-DC converter is shown in equation (2-14), which contains varying parameters. Based on the actual situation, we can assume their range is as follows:

[0150] (2-21)

[0151] Equation (2-14) lacks a disturbance quantity, so the ripple of the output voltage is assumed to be... It caused interference ripples satisfy:

[0152] (2-22)

[0153] Since the current ripple is a factor, the output voltage equation after interference is:

[0154] (2-23)

[0155] In equation (2-23) The outputs of the control system are all measurable quantities. This is to track the desired output voltage. Introducing an integral term , Since it is a dynamic output voltage, the system state variables can be set as follows:

[0156] (2-24)

[0157] Differentiating equation (2-23) gives:

[0158] (2-25)

[0159] Different vertices can be obtained from equation (2-19) The corresponding coefficient matrix, for example:

[0160] (2-26)

[0161] (2-27)

[0162] In the formula This represents the maximum value of the variable. The minimum value of the variable is given by equations (2-26) and (2-27), combined with the range of equation (2-21). According to equation (2-22), we can obtain:

[0163] (2-28)

[0164] make Then we have:

[0165] (2-29)

[0166] (2-30)

[0167] Strictly speaking, a three-phase dual active bridge DC-DC converter system is a discrete system because its control algorithm is often implemented by a digital controller such as an MCU, DSP, or FPGA. Furthermore, when using hybrid modulation, control quantity calculation is required, which relies heavily on the digital controller. Therefore, it is necessary to discretize equation (2-23) before designing robustness. The controller is more rational. It adopts Euler's forward formula, i.e. Discretizing equation (2-23) yields the following discretized state equation:

[0168] (2-31)

[0169] The polytopic representation of the coefficient matrix of equation (2-31) is as follows:

[0170] (2-32)

[0171] Consider state feedback control Substituting into equation (2-31), we obtain the closed-loop system:

[0172] (2-33)

[0173] in , .

[0174] Discrete systems The controller stability theorem is as follows:

[0175] Given There exists a matrix and positive definite symmetric matrix To satisfy LMIs:

[0176] (2-34)

[0177] Then the closed-loop system (2-23) gradually stabilizes, and from the disturbance arrive of Performance indicators are less than In the formula .

[0178] The system parameters in this embodiment are shown in Table 2 below.

[0179] Table 2. 3p-DAB Parameters

[0180]

[0181] Solve equation (2-34) using the Matlab LMI toolbox, where the settings are as follows: Finally, the controller is obtained. , The control block diagram of this embodiment is as follows: Figure 2 As shown in the figure For the control period is , Decoupling is achieved through a slow loop. .

[0182] like Figure 1 As shown, the hybrid modulation robust control method for the three-phase dual active bridge DC-DC converter in this embodiment includes:

[0183] Step 1, Obtain the target voltage Primary DC voltage and secondary DC voltage .

[0184] Step 2, the target voltage Input the robust controller and obtain the control output variable. For example... Figure 2 As shown, this step first involves setting the target voltage... With the secondary side DC voltage Coupling is performed, and the discrete integrator is input for integral tracking to help eliminate control errors caused by coupling and improve the system's response to the target voltage. Secondary DC voltage Adaptability of coordinated changes; then, the target voltage The output of the discrete integrator is input together with the output of the H∞ robust control loop to obtain the control output variable. This H∞ robust control loop can incorporate the target voltage. The output of the discrete integrator is combined with the output of the discrete integrator to produce a control output variable adapted to the characteristics of the 3p-DAB system. While suppressing system parameter fluctuations and external disturbances, the target voltage is guaranteed. and secondary DC voltage Control stability in coupled scenarios.

[0185] Step 3, based on the primary side DC voltage and secondary DC voltage Calculate the voltage turns ratio of a three-phase dual active bridge DC-DC converter. .

[0186] Step 4, set the control output variable and the voltage turns ratio of the three-phase dual active bridge DC converter The input is given to the hybrid modulation strategy controller to obtain the target primary-side duty cycle. Target secondary duty cycle Phase shift angles on both sides of the target The hybrid modulation strategy controller includes:

[0187] The first judgment unit is used to determine the voltage turns ratio of the three-phase dual active bridge DC converter. Is it equal to 1?

[0188] The first output unit is used to adjust the voltage turns ratio of the three-phase dual active bridge DC-DC converter. When the value is equal to 1, the SPS modulation strategy is used to output the target primary-side duty cycle. Target secondary duty cycle Phase shift angles on both sides of the target ;

[0189] The second output unit is used to adjust the voltage turns ratio of the three-phase dual active bridge DC-DC converter. When it is less than 1, according to the control output variable The target primary-side duty cycle is output using the analytical table of the control quantity according to the first hybrid modulation strategy. Target secondary duty cycle Phase shift angles on both sides of the target According to Table 1 Determine the control output variable in the part Which range does it fall within, and based on the control output variables? The calculation method corresponding to the falling range is to calculate the target's primary edge duty cycle. Target secondary duty cycle Phase shift angles on both sides of the target ;

[0190] The third output unit is used to adjust the voltage turns ratio of the three-phase dual active bridge DC-DC converter. When it is greater than 1, according to the control output variable The target primary-side duty cycle is output using the analytical table of the control quantity according to the second hybrid modulation strategy. Target secondary duty cycle Phase shift angles on both sides of the target According to Table 1 Determine the control output variable in the part Which range does it fall within, and based on the control output variables? The calculation method corresponding to the falling range is to calculate the target's primary edge duty cycle. Target secondary duty cycle Phase shift angles on both sides of the target .

[0191] Step 5, adjust the target primary edge duty cycle. Target secondary duty cycle Phase shift angles on both sides of the target The inputs are decoupled from their respective slow-loop controllers to obtain the primary-side duty cycle control quantity. Secondary duty cycle control quantity Phase shift angle control amount on both sides of the original and the secondary .

[0192] Step 6, using the primary side duty cycle control quantity Secondary duty cycle control quantity Phase shift angle control amount on both sides of the original and the secondary The three-phase dual active bridge DC converter is controlled.

[0193] like Figure 8 , Figure 9 and Figure 10 As shown, after applying the method of this embodiment, the system responds quickly with no significant overshoot at 40V output, remains stable without oscillation during sudden load changes, and exhibits smooth switching from 40V to 60V without fluctuations. Figure 11 As shown, within the entire scope of the strategy, the method of this implementation is more efficient than traditional SPS modulation and traditional hybrid modulation; as Figure 12As shown, the method of this embodiment is always the most efficient under full voltage turns ratio, and its advantages are even more obvious when the voltage turns ratio deviates from the rated state.

[0194] It is easy to see that the hybrid modulation of the present invention broadens the soft-switching range of the three-phase dual active bridge DC-DC converter, enabling it to have high efficiency over a wide output power range; robust control gives the three-phase dual active bridge DC-DC converter better anti-disturbance performance, thereby improving system robustness and giving the system a faster response speed, smaller steady-state error, and smaller overshoot.

[0195] The second embodiment of the present invention relates to a hybrid modulation robust control device for a three-phase dual active bridge DC-DC converter, comprising:

[0196] The acquisition module is used to acquire the target voltage, primary side DC voltage, and secondary side DC voltage.

[0197] The robust control module is used to input the target voltage into the robust controller to obtain the control output variable;

[0198] The calculation module is used to calculate the voltage ratio of the three-phase dual active bridge DC converter based on the primary side DC voltage and the secondary side DC voltage.

[0199] The hybrid modulation module is used to input the control output variable and the voltage ratio of the three-phase dual active bridge DC converter to the hybrid modulation strategy controller to obtain the target primary duty cycle, the target secondary duty cycle, and the phase shift angles of the target primary and secondary sides;

[0200] The decoupling module is used to decouple the target primary side duty cycle, the target secondary side duty cycle, and the phase shift angles on both sides of the target primary and secondary sides from their respective slow loop controllers to obtain the primary side duty cycle control quantity, the secondary side duty cycle control quantity, and the phase shift angle control quantity on both sides of the primary and secondary sides.

[0201] The control module is used to control the three-phase dual active bridge DC converter using the primary side duty cycle control quantity, the secondary side duty cycle control quantity, and the phase shift angle control quantities on both the primary and secondary sides.

[0202] The robust control module includes:

[0203] A discrete integrator unit is used to couple the target voltage with the secondary DC voltage and input it into the discrete integrator for integration tracking.

[0204] A robust control unit is used to input the target voltage and the output of the discrete integrator together into the H∞ robust control loop to obtain the control output variable.

[0205] The computing module passes through Calculate the voltage turns ratio of the three-phase dual active bridge DC-DC converter, where, This refers to the voltage turns ratio of a three-phase dual active bridge DC-DC converter. For transformer turns ratio, This is the secondary DC voltage. This is the primary side DC voltage.

[0206] The hybrid modulation strategy controller adopts a hybrid modulation strategy consisting of SPS modulation strategy and asymmetric duty cycle modulation strategy. The asymmetric duty cycle modulation strategy includes: triangular current Buck modulation, triangular current Boost modulation, trapezoidal current modulation and synchronous pulse width modulation.

[0207] The hybrid modulation strategy controller includes:

[0208] The first judgment unit is used to determine whether the voltage ratio of the three-phase dual active bridge DC converter is equal to 1;

[0209] The first output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides using an SPS modulation strategy when the voltage ratio of the three-phase dual active bridge DC converter is equal to 1.

[0210] The second output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides according to the control output variable using the first hybrid modulation strategy control quantity analysis table when the voltage ratio of the three-phase dual active bridge DC converter is less than 1.

[0211] The third output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides according to the control output variable using the second hybrid modulation strategy control quantity analysis table when the voltage ratio of the three-phase dual active bridge DC converter is greater than 1.

[0212] The first hybrid modulation strategy control quantity analysis table is as follows:

[0213]

[0214] in, To control the output variables, The target primary edge duty cycle, For the target secondary duty cycle, The phase shift angles on both sides of the target primary and secondary are... This refers to the voltage turns ratio of a three-phase dual active bridge DC-DC converter. , , , , , , , .

[0215] The second hybrid modulation strategy control quantity analysis table is as follows:

[0216]

[0217] in, To control the output variables, The target primary edge duty cycle, For the target secondary duty cycle, The phase shift angles on both sides of the target primary and secondary are... This refers to the voltage turns ratio of a three-phase dual active bridge DC-DC converter. , , , , , , , .

[0218] The third embodiment of the present invention relates to an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter of the first embodiment.

[0219] The fourth embodiment of the present invention relates to a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter of the first embodiment.

[0220] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0221] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0222] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction methods implemented in a process. Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0223] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0224] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter, characterized in that, Includes the following steps: Obtain the target voltage, primary-side DC voltage, and secondary-side DC voltage; The target voltage is input into the robust controller to obtain the control output variable; Calculate the voltage ratio of the three-phase dual active bridge DC converter based on the primary-side DC voltage and the secondary-side DC voltage; The control output variables and the voltage turns ratio of the three-phase dual active bridge DC-DC converter are input to the hybrid modulation strategy controller to obtain the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides. The hybrid modulation strategy controller adopts a hybrid modulation strategy composed of SPS modulation strategy and asymmetric duty cycle modulation strategy. The asymmetric duty cycle modulation strategy includes: triangular current Buck modulation, triangular current Boost modulation, trapezoidal current modulation, and synchronous pulse width modulation. The hybrid modulation strategy controller includes: The first judgment unit is used to determine whether the voltage ratio of the three-phase dual active bridge DC converter is equal to 1; The first output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides using an SPS modulation strategy when the voltage ratio of the three-phase dual active bridge DC converter is equal to 1. The second output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides according to the control output variable using the first hybrid modulation strategy control quantity analysis table when the voltage ratio of the three-phase dual active bridge DC converter is less than 1. The third output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides according to the control output variable using the second hybrid modulation strategy control quantity analysis table when the voltage ratio of the three-phase dual active bridge DC converter is greater than 1. The target primary side duty cycle, target secondary side duty cycle, and phase shift angles on both sides of the target primary and secondary sides are respectively input into their respective slow loop controllers for decoupling, to obtain the primary side duty cycle control quantity, secondary side duty cycle control quantity, and phase shift angle control quantity on both sides of the primary and secondary sides; The three-phase dual active bridge DC converter is controlled by the primary-side duty cycle control quantity, the secondary-side duty cycle control quantity, and the phase shift angle control quantities on both the primary and secondary sides.

2. The hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter according to claim 1, characterized in that, The step of inputting the target voltage into the robust controller to obtain the control output variable specifically includes: The target voltage is coupled to the secondary DC voltage and input into a discrete integrator for integration tracking. The target voltage and the output of the discrete integrator are input together into the H∞ robust control loop to obtain the control output variable.

3. The hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter according to claim 1, characterized in that, The voltage transformation ratio of the three-phase dual active bridge DC converter is achieved through... The calculation yielded that, This refers to the voltage turns ratio of a three-phase dual active bridge DC-DC converter. For transformer turns ratio, This is the secondary DC voltage. This is the primary side DC voltage.

4. The hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter according to claim 1, characterized in that, The first hybrid modulation strategy control quantity analysis table is as follows: in, To control the output variables, The target primary edge duty cycle, For the target secondary duty cycle, The phase shift angles on both sides of the target primary and secondary are... This refers to the voltage turns ratio of a three-phase dual active bridge DC-DC converter. , , , , , , , .

5. The hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter according to claim 1, characterized in that, The second hybrid modulation strategy control quantity analysis table is as follows: in, To control the output variables, The target primary edge duty cycle, For the target secondary duty cycle, The phase shift angles on both sides of the target primary and secondary are... This refers to the voltage turns ratio of a three-phase dual active bridge DC-DC converter. , , , , , , , .

6. A hybrid modulation robust control device for a three-phase dual active bridge DC-DC converter, characterized in that, include: The acquisition module is used to acquire the target voltage, primary side DC voltage, and secondary side DC voltage. The robust control module is used to input the target voltage into the robust controller to obtain the control output variable; The calculation module is used to calculate the voltage ratio of the three-phase dual active bridge DC converter based on the primary side DC voltage and the secondary side DC voltage. A hybrid modulation module is used to input the control output variable and the voltage transformation ratio of the three-phase dual active bridge DC converter to the hybrid modulation strategy controller to obtain the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both the primary and secondary sides. The hybrid modulation strategy controller adopts a hybrid modulation strategy composed of SPS modulation strategy and asymmetric duty cycle modulation strategy. The asymmetric duty cycle modulation strategy includes: triangular current Buck modulation, triangular current Boost modulation, trapezoidal current modulation, and synchronous pulse width modulation. The hybrid modulation strategy controller includes: The first judgment unit is used to determine whether the voltage ratio of the three-phase dual active bridge DC converter is equal to 1; The first output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides using an SPS modulation strategy when the voltage ratio of the three-phase dual active bridge DC converter is equal to 1. The second output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides according to the control output variable using the first hybrid modulation strategy control quantity analysis table when the voltage ratio of the three-phase dual active bridge DC converter is less than 1. The third output unit is used to output the target primary duty cycle, the target secondary duty cycle, and the phase shift angles on both sides of the target primary and secondary sides according to the control output variable using the second hybrid modulation strategy control quantity analysis table when the voltage ratio of the three-phase dual active bridge DC converter is greater than 1. The decoupling module is used to decouple the target primary side duty cycle, the target secondary side duty cycle, and the phase shift angles on both sides of the target primary and secondary sides from their respective slow loop controllers to obtain the primary side duty cycle control quantity, the secondary side duty cycle control quantity, and the phase shift angle control quantity on both sides of the primary and secondary sides. The control module is used to control the three-phase dual active bridge DC converter using the primary side duty cycle control quantity, the secondary side duty cycle control quantity, and the phase shift angle control quantities on both the primary and secondary sides.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter as described in any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the hybrid modulation robust control method for a three-phase dual active bridge DC-DC converter as described in any of claims 1-5.

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