A current decoupling control method for auxiliary inductor dual-buck half-bridge power amplifier

Abstract

A current decoupling control method for an auxiliary inductor dual-buck half-bridge power amplifier relates to the field of precision motor drive. The present invention controls the magnitude of the average current flowing through the auxiliary inductor to balance the current passing through the filter inductors on the two branches, thereby reducing the output current pulsation and further reducing the loss. The magnitudes of the currents in the two branches are set to constant values, so that the two branch currents output a half-cycle sine wave, and the branch output current does not pass through the zero point, thereby reducing the switching loss and harmonic distortion. The topological method of auxiliary increase in inductance can reduce the total inductance volume of the loop, and improve the problem of large inductance volume and weight caused by the DC bias magnetization of the inductor caused by the bias current. In addition, the auxiliary inductor current is added to the bias current of the loop, thereby reducing the nonlinear distortion of the system. The present invention improves the disadvantage of large inductance volume in the traditional dual-buck half-bridge inverter circuit loop, reduces the cost, and reduces the harmonic distortion of the circuit.

Description

Technical Field

[0001] The present invention relates to the field of precision motor driving, and in particular to a current decoupling control method for an auxiliary inductor dual-buck half-bridge power amplifier. Background Art

[0002] Compared with the traditional bridge inverter, the dual-buck half-bridge inverter has the advantages of no bridge arm direct pass, independent freewheeling diode instead of the body diode freewheeling of the switch tube, and no body diode reverse recovery. It has a small number of components, simple circuit topology and control method, and the half-cycle modulation method can reduce the loss of the switching device. However, the dual-buck inverter requires two independent filter inductors during normal operation, and the loop inductance is large in size. In addition, there are problems of uneven current and low-frequency pulsation on the input side during operation, which leads to voltage and current waveform distortion.

[0003] For example Figure 6 The figure shows a dual-step-down half-bridge inverter circuit, which solves the problem of the direct-through of the switch tube from the circuit structure itself. Therefore, the power switch device does not need to set a dead time, and can be freewheeling through an independent freewheeling diode. The circuit has greater interleaving flexibility, which can further reduce the amplitude of the output current ripple and achieve low harmonic distortion. However, compared with traditional power amplifiers, its inductor volume is larger, so the cost is also higher, and its switch device will produce certain losses during the conduction and shutdown process. The transient current generated by the switching loss will cause electromagnetic interference and cause the output current waveform to become unstable.

[0004] Therefore, how to solve the problems of large loop inductance, high cost, and voltage and current waveform distortion in the current dual-buck half-bridge inverter, and how to solve the problem of high switching power consumption in the control method of the traditional buck half-bridge inverter, is an urgent problem to be solved. Summary of the invention

[0005] The present invention aims to solve the problems of large loop inductance, high cost and voltage and current waveform distortion in the current dual-buck half-bridge inverter, and also to solve the problem of high switching power consumption in the control method of the traditional buck half-bridge inverter. A current decoupling control method for a dual-buck half-bridge power amplifier with an auxiliary inductor is provided.

[0006] The technical solution adopted by the present invention is:

[0007] A current decoupling control method based on an auxiliary inductor dual-buck half-bridge power amplifier is implemented based on an auxiliary inductor dual-buck half-bridge power amplifier. The amplifier is a dual-buck half-bridge power amplifier with an auxiliary inductor L added. b The dual-step-down half-bridge power amplifier is powered by two DC power supplies; its main circuit consists of two voltage-step-down inverter circuits, namely, a DC power supply Udc1 , power switch tube S1, filter inductor L1, filter capacitor C1 and freewheeling diode D1 form a step-down inverter circuit; the second DC power supply U dc2 , power switch tube S2, filter inductor L2, filter capacitor C2 and freewheeling diode D2 form another buck inverter circuit, and an auxiliary inductor L1 is connected in parallel between the filter inductors L1 and L2. b , and the auxiliary inductor L b The inductance value is 1 to 1.5 times the filter output inductance.

[0008] The current decoupling control method is:

[0009] Step 1: Collect the current value and voltage value in the auxiliary inductor dual-buck half-bridge power amplifier, that is, i1 and i2 represent the current flowing through the branch inductors L1 and L2, i b represents the current flowing through the auxiliary inductor L b The current, i out represents the output current, u1 and u2 represent the voltages of the two branch switch nodes, and the capacitor current i c ; Active damping compensation module K d ;

[0010] Step 2: i* out [Z] and output current i out After the difference is made, the difference between the two is obtained, and the difference is magnified by C out[ [Z] and after the active damping compensation module K d Compensation K d times the capacitor current i c After taking the difference, we get the output voltage U*out.

[0011] i* bias [Z] and i bias The difference between the two is obtained by subtracting the difference, which is magnified by C bias [Z] then get U* bias ;

[0012] i* b [Z] and i b The difference between the two is obtained by subtracting the difference, which is magnified by C b [Z] then get U* b ;

[0013] Step 3: The output voltage U*out, U* bias and U* b G -1 After the bridge coupling subsystem is calculated, U*1 and U*2 are obtained;

[0014] Step 4: U*1 is magnified K times to get m1, and U*2 is magnified K times to get m2;

[0015] Step 5: m1 and m2 are input to the PWM module and DBHBC module (dual buck half-bridge power converter), and the PWM module is used to output a PWM control signal to control the power switch tube S1 and the power switch tube S2;

[0016] Step 6: The DBHBC module outputs the current i1 flowing through the branch inductor L1, the current i2 flowing through the branch inductor L2, and the output current i out , i1, i2 and i out After being controlled by the H-bridge decoupling subsystem, the output capacitor current i c , output current i out 、i bias 、i b Then return to step 2.

[0017] Preferably, in step 3, the output voltages U*out and U* bias and U* b G -1 After the bridge coupling subsystem is calculated, the calculation process of U*1 is:

[0018]

[0019]

[0020] Preferably, in step 6, the DBHBC module outputs the current i1 flowing through the branch inductor L1, the current i2 flowing through the branch inductor L2, and the output current i out , i1, i2 and i out After being controlled by the H-bridge decoupling subsystem, the output capacitor current i c , output current i out 、i bias 、i b , where the H-bridge decoupling subsystem control process is:

[0021] i1+i2-i out =i c

[0022]

[0023] Preferably, out 、i1、i2、i b 、i bias 、i c The decoupling equations between are shown in the following equations:

[0024]

[0025] i out =i1+i2-i c (2).

[0026] Preferably, set i b , i1, i2 and bias current i th The size is given by the following equation:

[0027]

[0028]

[0029]

[0030] Preferably, the control current flowing through the auxiliary inductor L b The average current i b The size of i b , i1, i2 are set to constant values ​​to control i1, i2 to output half-cycle sinusoidal waveforms. The two branches of inductors work independently in half-cycle of power frequency, and the switch tube loss is small, which has higher system efficiency. Output current i out is a full cycle sine waveform. b It is a positive half-cycle waveform, which is used to balance the two branch currents i1 and i2, and at the same time reduce the output current of the filter inductor.

[0031] Preferably, the PWM control signal output by the PWM module in step 5 is generated in a triangular modulation mode, and the modulation method is: a triangular waveform is compared with a modulating waveform, and during the comparison process, if the amplitude of the triangular waveform is smaller than the modulating waveform, a high level is output; otherwise, a low level is output; the comparison process is completed in a comparator, and the output of the comparator is the final PWM signal;

[0032] The modulation index m is set to amplify the modulation waveform. m is equal to (2δ-1), where δ is the size of the PWM duty cycle. The duty cycle of the PWM signal is adjusted by changing the amplitude of the modulation waveform. A larger modulation waveform amplitude will result in a longer high-level time, thereby increasing the duty cycle.

[0033] Beneficial effects: The auxiliary inductor in the present invention improves the disadvantage of large inductor volume in the circuit loop of the traditional dual-buck half-bridge inverter, reduces the cost, and reduces the harmonic distortion of the circuit.

[0034] The current decoupling control method of the auxiliary inductor dual-buck half-bridge power amplifier described in the present invention can maintain the loop in a continuous conduction mode, minimize the loss caused by the auxiliary current, and avoid zero-crossing distortion.

[0035] By controlling the size of the average current flowing through the auxiliary inductor, the current passing through the filter inductors of the two branches is balanced, so that the output current pulsation is reduced, thereby reducing the loss. The current size of the two branches is set to a constant value, so that the two branches output a half-cycle sine wave, and the branch output current does not pass the zero point, reducing the switching loss and harmonic distortion. The topological method of auxiliary inductance can reduce the total inductance volume of the loop and improve the problem of DC bias magnetization of the inductor caused by the bias current, which leads to a larger inductance volume and weight. In addition, adding the auxiliary inductor current to the bias current of the loop reduces the nonlinear distortion of the system.

[0036] The present invention solves the problems of large loop inductance, high cost and voltage and current waveform distortion in the current dual-buck half-bridge inverter, and also solves the problem of high switch power consumption in the control method of the traditional buck half-bridge inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the topology of a dual-buck half-bridge inverter circuit with an auxiliary inductor branch;

[0038] Figure 2 It is the current decoupling control block diagram;

[0039] Figure 3 It's G -1 Schematic diagram of the bridge coupling subsystem control box;

[0040] Figure 4 It is a schematic diagram of the control box of the H-bridge decoupling subsystem;

[0041] Figure 5 is a schematic diagram of the output waveform;

[0042] Figure 6 It is a schematic diagram of a double voltage drop half-bridge inverter topology;

[0043] Figure 7 Schematic diagram of triangular modulation. DETAILED DESCRIPTION

[0044] Specific implementation method 1. Reference Figures 1 to 7 Specifically describe this embodiment, the current decoupling control method of an auxiliary inductor dual-buck half-bridge power amplifier described in this embodiment is based on an auxiliary inductor dual-buck half-bridge power amplifier, which is an amplifier that adds an auxiliary inductor L to the dual-buck half-bridge power amplifier. b ,The dual-buck half-bridge power amplifier is powered by two DC power supplies;

[0045] Its main circuit consists of two voltage-drop inverter circuits, namely, a DC power supply U dc1, power switch tube S1, filter inductor L1, filter capacitor C1 and freewheeling diode D1 form a step-down inverter circuit; the second DC power supply U dc2 , power switch tube S2, filter inductor L2, filter capacitor C2 and freewheeling diode D2 form another buck inverter circuit, and an auxiliary inductor L1 is connected in parallel between the filter inductors L1 and L2. b , and the auxiliary inductor L b The inductance value is 1 to 1.5 times the filter output inductance.

[0046] The current decoupling control method is:

[0047] Step 1: Collect the current value and voltage value in the auxiliary inductor dual-buck half-bridge power amplifier, that is, i1 and i2 represent the current flowing through the branch inductors L1 and L2, i b represents the current flowing through the auxiliary inductor L b The current, i out represents the output current, u1 and u2 represent the voltages of the two branch switch nodes, and the capacitor current i c ; Active damping compensation module K d ;

[0048] Step 2: i* out [Z] and output current i out After the difference is made, the difference between the two is obtained, and the difference is magnified by C out[ [Z] and after the active damping compensation module K d Compensation K d times the capacitor current i c After taking the difference, we get the output voltage U*out.

[0049] i* bias [Z] and i bias The difference between the two is obtained by subtracting the difference, which is magnified by C bias [Z] then get U* bias ;

[0050] i* b [Z] and i b The difference between the two is obtained by subtracting the difference, which is magnified by C b [Z] then get U* b ;

[0051] Step 3: The output voltage U*out, U* bias and U* b G -1 After the bridge coupling subsystem is calculated, U*1 and U*2 are obtained;

[0052] Step 4: U*1 is magnified K times to get m1, and U*2 is magnified K times to get m2;

[0053] Step 5: m1 and m2 are input to the PWM module and DBHBC module (dual buck half-bridge power converter), and the PWM module is used to output a PWM control signal to control the power switch tube S1 and the power switch tube S2;

[0054] Step 6: The DBHBC module outputs the current i1 flowing through the branch inductor L1, the current i2 flowing through the branch inductor L2, and the output current i out , i1, i2 and i out After being controlled by the H-bridge decoupling subsystem, the output capacitor current i c , output current i out 、i bias 、i b Then return to step 2.

[0055] The amplifier of the present invention adds an auxiliary inductor L to the dual-step-down half-bridge power amplifier. b The disadvantage of the large inductor volume in the traditional double-buck half-bridge inverter circuit loop is improved, the cost is reduced, and the harmonic distortion of the circuit is reduced. This is because:

[0056] First, the volume of the inductor is proportional to the inductor current. The additional inductance has a current-sharing effect, which reduces the current flowing through the filter inductor, thus reducing the volume of the inductor. According to the current distribution theory, the distribution of the bias current depends on the series filter inductor (L1, L2) and the bias inductor L b The impedance relationship between them. According to the distribution relationship, the current distribution factors Q1 and Q2 are designed as follows:

[0057]

[0058]

[0059] Based on this, the inductor volume value of this design is determined. According to existing common knowledge, when There is an optimal relationship when The volume of the inductor in this topology has been reduced by 39% compared to the volume of the inductor in the traditional dual buck circuit. b When the inductor and resistor are infinitesimally small, the smallest inductor volume can be obtained. Due to the limited resolution of the PWM modulator, L b The ripple current in will be infinite, so L is selected here. b The inductance value is 1 to 1.5 times of the filter output inductance. This solves the problem of large inductance volume in the traditional double-buck half-bridge inverter circuit loop, reduces costs, and reduces harmonic distortion of the circuit.

[0060] In this embodiment, the auxiliary inductor dual-buck half-bridge power amplifier of the present invention adopts a dual-buck inverter topology, and the current of the two branch inductors is a single-phase output. By injecting a bias current into the loop, the current of the filter inductor is always in a continuous conduction state, ensuring the linear input and output state of the circuit, thereby eliminating the current zero-crossing distortion and ensuring a low-harmonic output current. The increased auxiliary inductor current can balance the current of the filter inductors passing through the two branches and reduce the volume of the loop inductor. Figure 1 As shown, i1 and i2 represent the current flowing through the branch inductors L1 and L2, i b represents the current flowing through the auxiliary inductor i b The current, i out represents the output current, u1 and u2 represent the voltages of the two branch switch nodes.

[0061] The dual-buck half-bridge inverter circuit topology with auxiliary inductor branch is as follows Figure 2 As shown in the figure, this topology is powered by a positive DC power supply and consists of a half-bridge, dual-buck topology, MOSFET, inductor, and diode. Its main circuit consists of two voltage-drop circuits, namely, the power supply U dc , power switch tube S1, filter inductor L1, filter capacitor C1 and freewheeling diode D1 form a step-down inverter circuit; the power supply U dc , power switch tube S2, filter inductor L2, filter capacitor C2 and freewheeling diode D2 form another buck inverter circuit, and add auxiliary inductor L1 and L2 to the output filter inductor b Among them, the auxiliary inductor L b The inductance value is about 1 to 1.5 times the filter output inductance.

[0062] Working principle: In the auxiliary inductor dual-buck half-bridge power amplifier, the filter inductor L1 and the filter inductor L2 output unidirectional current (one for providing positive load current and the other for providing negative current) are integrated to run in parallel to form a topology covering bidirectional power flow. The amplifier circuit topology of the present invention adopts a half-cycle bias current mode. In the half-cycle mode, the two Buck circuits work alternately, and the switching devices are turned on in their respective corresponding current cycles. The variable parameter bias current control makes the inductor current of the circuit always in a continuous conduction mode. By adjusting the duty cycle of the pulse width modulation (PWM) to determine the modulation index of the output current, the modulation of the steady-state inductor output current ripple amplitude is achieved, and the magnitude of the bias current is determined based on the transient magnitude of the output current.

[0063] In this embodiment, the bias current decoupling control block diagram is as follows: Figure 3 As shown, the linear decoupling control of the output current and bias current of the circuit is utilized, and the circuit topology is combined with the feedforward and feedback technology and the active damping compensation module K dThe bias current decoupling control output waveform does not have the distortion caused by the dead zone and the odd harmonics generated in the traditional bridge amplifier, which reduces the total harmonic distortion of the output current. The switches are grouped and only two groups of drive signals are used to achieve low harmonic distortion, reducing the complexity of the system.

[0064] This control method maintains the loop in continuous conduction mode by adding bias current to the loop. The coupling equations between the output parameters are established and the branch current and the auxiliary inductor current are controlled, so that the branch current outputs a half-cycle sine wave, reducing switching losses and harmonic distortion. In addition, the auxiliary inductor of the branch can carry the branch inductor current, reducing the output current pulsation and thus reducing losses.

[0065] Specific implementation method 2: This implementation method is a further description of the current decoupling control method of the auxiliary inductor dual-buck half-bridge power amplifier described in implementation method 1. In step 3, the output voltage U*out, U* bias and U* b G -1 After the bridge coupling subsystem is calculated, the calculation process of U*1 is:

[0066]

[0067]

[0068] Specific implementation method three, this implementation method is a further description of the current decoupling control method of the auxiliary inductor dual buck half-bridge power amplifier described in implementation method one, in step six, the DBHBC module outputs the current i1 flowing through the branch inductor L1, the current i2 flowing through the branch inductor L2 and the output current i out , i1, i2 and i out After being controlled by the H-bridge decoupling subsystem, the output capacitor current i c , output current i out 、i bias 、i b , where the H-bridge decoupling subsystem control process is:

[0069] i1+i2-i out =i c

[0070]

[0071] Specific implementation method 4: This implementation method is a further description of the current decoupling control method of the auxiliary inductor dual-buck half-bridge power amplifier described in the implementation method 1.

[0072] i out 、i1、i2、i b、i bias 、i c The decoupling equations between are shown in the following equations:

[0073]

[0074] i out =i1+i2-i c (2).

[0075] Specific implementation mode 5: This implementation mode is a further description of the current decoupling control method of the auxiliary inductor dual-buck half-bridge power amplifier described in the implementation mode 1.

[0076] Setting b , i1, i2 and bias current i th The size is given by the following equation:

[0077]

[0078]

[0079]

[0080] Specific implementation method 6: This implementation method is a further description of the current decoupling control method of the auxiliary inductor dual-buck half-bridge power amplifier described in the implementation method 1.

[0081] Control the current flowing through the auxiliary inductor L b The average current i b The size of i b , i1, i2 are set to constant values ​​to control i1, i2 to output half-cycle sinusoidal waveforms. The two branches of inductors work independently in half-cycle of power frequency, and the switch tube loss is small, which has higher system efficiency. Output current i out is a full cycle sine waveform. b It is a positive half-cycle waveform, which is used to balance the two branch currents i1 and i2, and at the same time reduce the output current of the filter inductor.

[0082] The current decoupling control method of the present application is as follows: auxiliary inductor balance, the current through L1 and L2, so that each filter inductor conducts only half of the output current. In order to balance the filter inductor current, the current through L b The average current,

[0083] Assume that the current ripple of each filter inductor is completely absorbed by the filter capacitor, and assume that i C is zero, and the decoupling equations between the parameters are obtained by establishing the state control equation:

[0084] The decoupling method of the present invention can directly realize independent control of the output current, the branch current and the bias circuit without defining virtual variables.

[0085] Specific implementation manner VII: This implementation manner is a further description of the current decoupling control method of the auxiliary inductor dual-buck half-bridge power amplifier described in implementation manner 1.

[0086] The PWM module in step 5 generates the PWM control signal in a triangular modulation mode, and the modulation method is: compare a triangular waveform with a modulating waveform, and in the comparison process, if the amplitude of the triangular waveform is smaller than the modulating waveform, a high level is output; otherwise, a low level is output; the comparison process is completed in a comparator, and the output of the comparator is the final PWM signal;

[0087] The modulation index m is set to amplify the modulation waveform. m is equal to (2δ-1), where δ is the size of the PWM duty cycle. The duty cycle of the PWM signal is adjusted by changing the amplitude of the modulation waveform. A larger modulation waveform amplitude will result in a longer high-level time, thereby increasing the duty cycle.

[0088] The PWM control signal generation method of the present invention is triangular modulation. Figure 7 As shown in the figure, a triangular waveform is compared with a modulating waveform. During the comparison process, if the amplitude of the triangular waveform is smaller than the modulating waveform, a high level is output; otherwise, a low level is output. This comparison operation is usually completed in a comparator, and the output of the comparator is the final PWM signal. The modulation index m is set to amplify the modulating waveform. m is equal to (2δ-1), where δ is the size of the PWM duty cycle. The duty cycle of the PWM signal can be adjusted by changing the amplitude of the modulating waveform. A larger amplitude of the modulating waveform will result in a longer high level time, thereby increasing the duty cycle.

[0089] The present invention is described by several specific embodiments, and it should be understood by those skilled in the art that various changes and equivalent substitutions may be made to the present invention without departing from the scope of the present invention. In addition, various modifications may be made to the present invention for specific situations or specific circumstances without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed, but should include all implementation methods falling within the scope of the claims of the present invention.

Claims

1. A current decoupling control method for an auxiliary inductor dual-buck half-bridge power amplifier, characterized in that: The method is based on an auxiliary inductor dual-buck half-bridge power amplifier, which is a dual-buck half-bridge power amplifier with an auxiliary inductor L added. b The dual-step-down half-bridge power amplifier is powered by two DC power supplies; its main circuit consists of two voltage-step-down inverter circuits, namely, a DC power supply U dc1 , power switch tube S1, filter inductor L1, filter capacitor C1 and freewheeling diode D1 form a step-down inverter circuit; the second DC power supply U dc2 , power switch tube S2, filter inductor L2, filter capacitor C2 and freewheeling diode D2 form another buck inverter circuit, and an auxiliary inductor L1 is connected in parallel between the filter inductors L1 and L2. b , and the auxiliary inductor L b The inductance value is 1 to 1.5 times the filter output inductance; The current decoupling control method is: Step 1: Collect the current value and voltage value in the auxiliary inductor dual-buck half-bridge power amplifier, that is, i1 and i2 represent the current flowing through the branch inductors L1 and L2, i b represents the current flowing through the auxiliary inductor L b The current, i out represents the output current, u1 and u2 represent the voltages of the two branch switch nodes, and the capacitor current i c ; Active damping compensation module K d ; Step 2: i* out [Z] and output current i out After the difference is made, the difference between the two is obtained, and the difference is magnified by C out[ [Z] and after the active damping compensation module K d Compensation K d times the capacitor current i c After taking the difference, we get the output voltage U*out. i* bias [Z] and i bias The difference between the two is obtained by subtracting the difference, which is magnified by C bias [Z] then get U* bias ; i* b [Z] and i b The difference between the two is obtained by subtracting the difference, which is magnified by C b [Z] then get U* b ; Step 3: The output voltage U*out, U* bias and U* b G -1 After the bridge coupling subsystem is calculated, U*1 and U*2 are obtained; In step 3, the output voltages U*out and U* bias and U* b G -1 After the bridge coupling subsystem is calculated, the calculation process of U*1 is: Step 4: U*1 is magnified K times to get m1, and U*2 is magnified K times to get m2; Step 5: m1 and m2 are input to the PWM module and DBHBC module (double-drop half-bridge power converter), and the PWM module is used to output a PWM control signal to control the power switch tube S1 and the power switch tube S2; Step 6: The DBHBC module outputs the current i1 flowing through the branch inductor L1, the current i2 flowing through the branch inductor L2, and the output current i out , i1, i2 and i out After being controlled by the H-bridge decoupling subsystem, the output capacitor current i c , output current i out 、i bias 、i b Then return to step 2; In step 6, the DBHBC module outputs the current i1 flowing through the branch inductor L1, the current i2 flowing through the branch inductor L2, and the output current i out , i1, i2 and i out After being controlled by the H-bridge decoupling subsystem, the output capacitor current i c , output current i out 、i bias 、i b , where the H-bridge decoupling subsystem control process is: i1+i2-i out =i c 2. The current decoupling control method of the auxiliary inductor dual-buck half-bridge power amplifier according to claim 1, characterized in that: i out 、i1、i2、i b 、i bias 、i c The decoupling equations between are shown in the following equations: i out =i1+i2-i c (2)。 3. The current decoupling control method of the auxiliary inductor dual-buck half-bridge power amplifier according to claim 1, characterized in that: Setting b , i1, i2 and bias current i th The size is given by the following equation:

4. The current decoupling control method of the auxiliary inductor dual-buck half-bridge power amplifier according to claim 1, characterized in that: Control the current flowing through the auxiliary inductor L b The average current i b The size of i b The values ​​of i1 and i2 are set to constant values ​​to control i1 and i2 to output half-cycle sinusoidal waveforms. The two branches of inductors work independently in half-cycle of the power frequency. The switch tube loss is small, and the system efficiency is higher. The output current i out is a full-cycle sine waveform; i b It is a positive half-cycle waveform, which is used to balance the two branch currents i1 and i2, and at the same time reduce the output current of the filter inductor.

5. The current decoupling control method of the auxiliary inductor dual-buck half-bridge power amplifier according to claim 1, characterized in that: The PWM module in step 5 generates the PWM control signal in a triangular modulation mode, and the modulation method is: compare a triangular waveform with a modulating waveform, and in the comparison process, if the amplitude of the triangular waveform is smaller than the modulating waveform, a high level is output; otherwise, a low level is output; the comparison process is completed in a comparator, and the output of the comparator is the final PWM signal; The modulation index m is set to amplify the modulation waveform. m is equal to (2δ-1), where δ is the size of the PWM duty cycle. The duty cycle of the PWM signal is adjusted by changing the amplitude of the modulation waveform. A larger modulation waveform amplitude will result in a longer high-level time, thereby increasing the duty cycle.

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