Control method and device of bidirectional cllc resonant converter

Abstract

The application provides a control method and device of a bidirectional CLLC resonant converter, the method comprising: acquiring an actual output voltage of the bidirectional CLLC resonant converter, and acquiring a given voltage, and calculating an error voltage between the given voltage and the actual output voltage, wherein the given voltage is a target output voltage of the bidirectional CLLC resonant converter; inputting the error voltage into a phase compensator to obtain an output voltage of the phase compensator; inputting the output voltage of the phase compensator into a PI controller for voltage closed-loop control with frequency as a control quantity to obtain a target operating frequency of the bidirectional CLLC resonant converter in a next control period; and controlling the bidirectional CLLC resonant converter according to the target operating frequency. Thus, the control of the bidirectional CLLC resonant converter is realized through the phase compensator and the PI controller, which can not only improve the loop phase margin, improve the loop bandwidth, and improve the dynamic response characteristics of the bidirectional CLLC resonant converter, but also facilitate the acquisition of parameters.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric energy conversion, and in particular to a control method of a bidirectional CLLC resonant converter and a control device of the bidirectional CLLC resonant converter. BACKGROUND

[0002] With the continuous development of new energy technology, the application scenarios of power electronic devices are changing, the bidirectional DC conversion technology is developing, and the bidirectional DC converter becomes a very important role in power distribution, power transformation and other power consumption scenarios. Its application is more and more widely used, and the technical requirements are also continuously improved. How to stably and reliably control the bidirectional electric energy converter, especially the bidirectional CLLC resonant converter, has become a hot issue at present.

[0003] In the related art, the bidirectional CLLC resonant converter is usually controlled by a zero-pole controller to improve the low-frequency characteristics by designing the zero-pole positions of the controller. However, there are many variables in the method, and it is not easy to obtain more appropriate parameters. SUMMARY

[0004] To solve one of the above technical problems, the present application proposes the following technical solutions.

[0005] The first aspect of the present application provides a control method of a bidirectional CLLC resonant converter, comprising: obtaining an actual output voltage of the bidirectional CLLC resonant converter, and obtaining a given voltage, and calculating an error voltage between the given voltage and the actual output voltage, wherein the given voltage is a target output voltage of the bidirectional CLLC resonant converter; inputting the error voltage into a phase compensator to obtain an output voltage of the phase compensator; inputting the output voltage of the phase compensator into a PI (Proportion Integration) controller for voltage closed-loop control with frequency as a control quantity to obtain a target operating frequency of the bidirectional CLLC resonant converter in the next control period; and controlling the bidirectional CLLC resonant converter according to the target operating frequency.

[0006] In addition, the control method of the bidirectional CLLC resonant converter according to the above embodiments of the present application can also have the following additional technical features.

[0007] According to one embodiment of the present application, the compensation formula of the phase compensator is:

[0008]

[0009] wherein f z is the frequency corresponding to the zero point in the phase compensator, and f p is the frequency corresponding to the pole point in the phase compensator.

[0010] According to one embodiment of the present application, the frequency corresponding to the zero point in the phase compensator and the frequency corresponding to the pole in the phase compensator are calculated according to the following formula:

[0011] f z = 1.15f mr

[0012] f p = 10f mr

[0013] wherein f mr is the loop characteristic frequency.

[0014] According to one embodiment of the present application, the loop characteristic frequency is calculated according to the following formula:

[0015]

[0016] wherein L r is the primary side resonant inductance in the bidirectional CLLC resonant converter, L rs is the secondary side resonant inductance in the bidirectional CLLC resonant converter, C o is the output capacitance in the bidirectional CLLC resonant converter, and n is the turns ratio of the transformer in the bidirectional CLLC resonant converter.

[0017] According to one embodiment of the present application, the bidirectional CLLC resonant converter is controlled according to the target operating frequency, including: configuring a primary side driving pulse signal of the bidirectional CLLC resonant converter according to the target operating frequency; converting the primary side driving pulse signal into a switch driving signal by a pulse driving circuit in the bidirectional CLLC resonant converter, and controlling the conduction or turn-off of a primary side switch in the bidirectional CLLC resonant converter by the switch driving signal.

[0018] The second aspect embodiment of the present application proposes a control device of a bidirectional CLLC resonant converter, including: an acquisition module, configured to acquire an actual output voltage of the bidirectional CLLC resonant converter, and acquire a given voltage, and calculate an error voltage between the given voltage and the actual output voltage, wherein the given voltage is a target output voltage of the bidirectional CLLC resonant converter; a first input module, configured to input the error voltage into a phase compensator to obtain an output voltage of the phase compensator; a second input module, configured to input the output voltage of the phase compensator into a PI controller for voltage closed loop control with frequency as a control quantity to obtain a target operating frequency of the bidirectional CLLC resonant converter in a next control period; and a control module, configured to control the bidirectional CLLC resonant converter according to the target operating frequency.

[0019] In addition, the control device of the bidirectional CLLC resonant converter according to the above-mentioned embodiment of the present application can further have the following additional technical features.

[0020] According to one embodiment of the present application, the compensation formula of the phase compensator is:

[0021]

[0022] wherein f z is the frequency corresponding to the zero point in the phase compensator, and f p is the frequency corresponding to the pole point in the phase compensator.

[0023] According to one embodiment of the present application, the control device of the bidirectional CLLC resonant converter further comprises a first calculation module configured to calculate the frequency corresponding to the zero point in the phase compensator and the frequency corresponding to the pole point in the phase compensator according to the following formula:

[0024] f z = 1.15f mr

[0025] f p = 10f mr

[0026] wherein f mr is the loop characteristic frequency.

[0027] According to one embodiment of the present application, the control device of the bidirectional CLLC resonant converter further comprises a second calculation module configured to calculate the loop characteristic frequency according to the following formula:

[0028]

[0029] wherein L r is the primary side resonant inductance in the bidirectional CLLC resonant converter, L rs is the secondary side resonant inductance in the bidirectional CLLC resonant converter, C o is the output capacitance in the bidirectional CLLC resonant converter, and n is the turns ratio of the transformer in the bidirectional CLLC resonant converter.

[0030] According to one embodiment of the present application, the control module is specifically configured to: configure the primary side driving pulse signal of the bidirectional CLLC resonant converter according to the target operating frequency; convert the primary side driving pulse signal into a switch driving signal through a pulse driving circuit in the bidirectional CLLC resonant converter, and control the conduction or turn-off of the primary side switch in the bidirectional CLLC resonant converter by using the switch driving signal.

[0031] The technical solution of this invention first calculates the error voltage between the target output voltage and the actual output voltage of the bidirectional CLLC resonant converter. This error voltage is then input to a phase compensator. After obtaining the output voltage of the phase compensator, this output voltage is input to a PI controller for closed-loop voltage control. This yields the target operating frequency for the next control cycle of the bidirectional CLLC resonant converter. The bidirectional CLLC resonant converter is then controlled based on this target operating frequency. Therefore, by using the phase compensator and PI controller, the bidirectional CLLC resonant converter can be controlled, which not only improves the loop phase margin and loop bandwidth, enhancing the dynamic response characteristics of the bidirectional CLLC resonant converter, but also facilitates the convenient acquisition of parameters. Attached Figure Description

[0032] Figure 1A This is a schematic diagram of the bidirectional CLLC resonant converter according to an embodiment of the present invention.

[0033] Figure 1A This is a simplified topology diagram of the bidirectional CLLC resonant converter according to an embodiment of the present invention.

[0034] Figure 2 This is a schematic diagram of the controller of the bidirectional CLLC resonant converter according to an embodiment of the present invention.

[0035] Figure 3 This is a flowchart of the control method for a bidirectional CLLC resonant converter according to an embodiment of the present invention.

[0036] Figure 4 This is a schematic diagram illustrating the working principle of the phase compensator + PI controller in an embodiment of the present invention.

[0037] Figure 5 Bode plot of frequency perturbation versus output voltage obtained by PLECS frequency sweep for bidirectional CLLC resonant converter.

[0038] Figure 6 The open-loop Bode plot is obtained by sweeping the frequency using the PI controller + phase compensator control scheme of this embodiment of the invention for the bidirectional CLLC resonant converter.

[0039] Figure 7 The open-loop Bode plot is obtained by sweeping the frequency using a PI controller control scheme for a bidirectional CLLC resonant converter.

[0040] Figure 8 The output voltage and output current waveforms are dynamically loaded using a PI controller + phase compensator control scheme.

[0041] Figure 9 This is a block diagram of the control device for a bidirectional CLLC resonant converter according to an embodiment of the present invention. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Figure 1A This is a schematic diagram of the bidirectional CLLC resonant converter according to an embodiment of the present invention.

[0044] like Figure 1A As shown, this bidirectional CLLC resonant converter (also known as a CLLC bidirectional DC-DC converter) includes: a DC input power supply Vin, primary-side switching transistors (S1~S4), and a primary-side resonant inductor L. r Primary resonant capacitor C r Magnetizing inductance L m Transformer (turn ratio n), secondary resonant inductor L rs Secondary resonant capacitor C rs Secondary-side switching transistors (V1~V4), output capacitor C o and output load resistance R o , where V o This is the actual output voltage of the bidirectional CLLC resonant converter. For the connection methods between the various electronic components, please refer to [reference needed]. Figure 1A .

[0045] Figure 1B This is a simplified topology diagram of a bidirectional CLLC resonant converter according to an embodiment of the present invention. Wherein, v in For V in The AC voltage after inversion, where n is the transformer turns ratio.

[0046] It should be noted that in practical applications, the controller of the bidirectional CLLC resonant converter controls the voltage conversion of the bidirectional CLLC resonant converter by controlling the conduction and cutoff of each switch of the bidirectional CLLC resonant converter.

[0047] Figure 2 This is a schematic diagram of the controller of the bidirectional CLLC resonant converter according to an embodiment of the present invention.

[0048] like Figure 2As shown, the controller can use DSP20049C as the core control chip and also includes an ADC (Analog-to-Digital Converter) sampling circuit, a phase compensator, and a PI (Proportion Integration) controller. The controller may also include a protection unit for protection purposes. Figure 2 V in ref V is the target output voltage of the bidirectional CLLC resonant converter. o V is the actual output voltage of the bidirectional CLLC resonant converter. eer For the target output voltage V ref With the actual output voltage V o The difference between them is the error voltage.

[0049] In this embodiment of the invention, the controller of the bidirectional CLLC resonant converter can control the primary-side switching transistors of the bidirectional CLLC resonant converter in operation, thereby improving the control performance of the bidirectional CLLC resonant converter when it is operating in the forward direction.

[0050] Figure 3 This is a flowchart of the control method for a bidirectional CLLC resonant converter according to an embodiment of the present invention.

[0051] like Figure 3 As shown, the control method of the bidirectional CLLC resonant converter includes the following steps S1 to S4.

[0052] S1, obtain the actual output voltage of the bidirectional CLLC resonant converter, obtain the given voltage, and calculate the error voltage between the given voltage and the actual output voltage, where the given voltage is the target output voltage of the bidirectional CLLC resonant converter.

[0053] Among them, the target output voltage V ref This can be understood as the required output voltage of the bidirectional CLLC resonant converter, which is the theoretical value; the actual output voltage V... o This can be understood as the actual output voltage of the bidirectional CLLC resonant converter when it is working, which is the actual value.

[0054] Specifically, when the bidirectional CLLC resonant converter is operating, the target output voltage V of the bidirectional CLLC resonant converter can be obtained. ref The actual output voltage V of the bidirectional CLLC resonant converter is obtained through the ADC sampling circuit. o Then calculate V ref With V o Error voltage V between err .

[0055] S2 inputs the error voltage into the phase compensator to obtain the output voltage of the phase compensator.

[0056] Specifically, such as Figure 4 As shown, in V ref With V o Error voltage V between err Then, the error voltage V err Input phase compensator, Figure 4 China G pc (s) is the transfer function of the phase compensator, and the phase compensator performs phase compensation to obtain the output voltage V of the phase compensator. o1 The output voltage V can be o1 The input is given to the PI controller.

[0057] S3 inputs the output voltage of the phase compensator into the PI controller for closed-loop voltage control with frequency as the control variable, so as to obtain the target operating frequency of the bidirectional CLLC resonant converter in the next control cycle.

[0058] The target operating frequency can be understood as the frequency required for the primary-side switching transistors of the bidirectional CLLC resonant converter to operate.

[0059] Specifically, refer to Figure 4 After obtaining the output voltage V of the phase compensator o1 After that, V o1 The input scaling parameter is k p The integration parameter is k i PI controller, Figure 4 China G pi (s) is the transfer function of the PI controller. Figure 4 In the middle, V ref This refers to the desired or setpoint value when the PI controller is in operation, and the actual output voltage V. o This is the feedback value when the PI controller performs control. The PI controller receives the output voltage V... o1 Then, voltage closed-loop control is performed using frequency as the control variable. During the control process, the actual output voltage V of the input phase compensator is used. o The change, in turn, inputs the output voltage V of the PI controller. o1 Change until the output voltage V o1 When the value is close to 0, the feedback value is equal to the given value. At this point, the output of the PI controller is the target operating frequency f of the bidirectional CLLC resonant converter for the next control cycle. s (kHz).

[0060] The transfer function of the PI controller is:

[0061]

[0062] In the formula, k p k is the proportional parameter of the PI controller. i These are the integral parameters of the PI controller.

[0063] In this embodiment of the invention, the PI controller parameters can be obtained during the actual debugging process, the parameters are few, and the debugging is simple.

[0064] S4 controls the bidirectional CLLC resonant converter according to the target operating frequency.

[0065] Specifically, after obtaining the target operating frequency of the next control cycle of the bidirectional CLLC resonant converter, the switching transistor drive signal can be obtained according to the target operating frequency. The switching transistor drive signal is used to control the primary-side switching transistors (S1 to S4) of the bidirectional CLLC resonant converter to turn on and off, thereby realizing inversion.

[0066] In this embodiment of the invention, when the bidirectional CLLC resonant converter is operating in the forward direction, the phase compensator performs phase compensation on the error voltage between the voltage setpoint and the actual voltage output value to obtain the output voltage of the phase compensator. The output voltage of the phase compensator is then input to the PI controller. The PI controller performs closed-loop voltage control based on the error signal and uses frequency as the control quantity to obtain the target operating frequency of the bidirectional CLLC resonant converter for the next control cycle. The controller then controls the primary-side switching transistors (S1 to S4) to turn on and off according to the target operating frequency to achieve inversion in the next control cycle. It should be noted that at this time, no control signal is applied to the secondary-side switching transistors (V1 to V4), and the rectification function is achieved through the anti-parallel diodes on the secondary side.

[0067] This invention employs a control scheme using a PI controller and a phase compensator to determine the target operating frequency of the primary-side switch in the next control cycle. The phase compensator improves the loop phase margin and increases the loop bandwidth. When controlling the primary-side switch at the target operating frequency, it can ensure a certain voltage regulation range for the bidirectional CLLC resonant converter and achieve stable and reliable control of the bidirectional CLLC resonant converter. This improves the system loop bandwidth and control performance, and has the advantages of simple implementation and convenient parameter acquisition.

[0068] Therefore, the control method of the bidirectional CLLC resonant converter in this embodiment of the invention, through the phase compensator and PI controller, realizes the control of the bidirectional CLLC resonant converter, which can not only improve the loop phase margin, improve the loop bandwidth, and enhance the dynamic response characteristics of the bidirectional CLLC resonant converter, but also facilitates the convenient acquisition of parameters.

[0069] In one embodiment of the present invention, the compensation formula of the phase compensator is:

[0070]

[0071] Among them, f z f is the frequency corresponding to the zero point in the phase compensator. p These are the frequencies corresponding to the poles in the phase compensator, and both frequencies are related to the loop characteristic frequency f. mr correspond.

[0072] The frequencies corresponding to the zeros and poles in the phase compensator are calculated using the following formulas:

[0073] f z =1.15f mr (3)

[0074] f p =10f mr (4)

[0075] Among them, f mr The loop characteristic frequency is calculated using the following formula:

[0076]

[0077] Among them, L r L is the primary resonant inductor in a bidirectional CLLC resonant converter. rs C is the secondary resonant inductor in a bidirectional CLLC resonant converter. o denoted as the output capacitor in the bidirectional CLLC resonant converter, and n is the turns ratio of the transformer in the bidirectional CLLC resonant converter.

[0078] As can be seen, the frequencies corresponding to the zeros and poles in the phase compensator can be determined based on the specific physical parameters of the loop, which is simple and easy to obtain.

[0079] In one embodiment of the present invention, step S4 may include: configuring the primary-side drive pulse signal of the bidirectional CLLC resonant converter according to the target operating frequency; converting the primary-side drive pulse signal into a switch drive signal through the pulse drive circuit in the bidirectional CLLC resonant converter, and controlling the on or off of the primary-side switch in the bidirectional CLLC resonant converter with the switch drive signal.

[0080] Specifically, after the PI controller outputs the target operating frequency through voltage closed-loop control, it configures the primary-side drive pulse signal (the pulse signal that controls the turn-on and turn-off of the primary-side switching transistors) of the bidirectional CLLC resonant converter according to the target operating frequency, and can send the primary-side drive pulse signal to the pulse drive circuit. After receiving the primary-side drive pulse signal, the pulse drive circuit converts the signal into a switching transistor drive signal, and uses the switching transistor drive signal to control the turn-on and turn-off of the primary-side switching transistors (S1~S4) in the bidirectional CLLC resonant converter, thereby realizing inversion.

[0081] To effectively verify the control method of the bidirectional CLLC resonant converter proposed in this embodiment of the invention, a simulation model was built in PLECE software and simulation verification was performed. The loop sweep Bode plot of the bidirectional CLLC resonant converter operating at the resonant frequency was tested. The bidirectional CLLC resonant converter was controlled using a PI controller scheme and a PI controller + phase compensator scheme, and loop sweep comparisons were performed. The simulation circuit parameters are shown in Table 1. The specific experimental conditions were: a constant input voltage of 400V, a target output voltage of 400V for closed-loop control, and the controller output frequency value in kHz. Table 1 shows the basic circuit parameters of the verification model.

[0082] Table 1

[0083] CLLC topology parameters Parameter value Primary resonant inductance L r (H)] 25e-6 Primary resonant capacitor C r (F)] 210e-9 Secondary side resonant inductance L rs (H)] 25e-6 Secondary side resonant capacitor C rs (F)] 210e-9 Excitation inductance L m (H)] 120e-6 Transformer ratio n: 1 1:1 Operating frequency range (kHz) 50～150 Load resistance Ro (Ω) 90 Dead time T db (ns) 250 Controller parameter kp -0.6 Controller parameter ki -2*pi*250*0.6 Phase compensator zero f z (Hz) 1840 Phase compensator pole f p (Hz) 16000

[0084] Figure 5 Bode plot of frequency perturbation versus output voltage obtained by PLECS frequency sweep for bidirectional CLLC resonant converter. Figure 6 The open-loop Bode plot of the bidirectional CLLC resonant converter obtained by frequency sweeping using the PI controller + notch filter control scheme of this embodiment of the invention. Figure 7 The open-loop Bode plot is obtained by frequency sweeping using a PI controller control scheme for a bidirectional CLLC resonant converter. Figure 8 The output voltage and current waveforms are shown for a PI controller + phase compensator control scheme. The Bode plot includes an amplitude-frequency response curve (Frequency-Magnitude curve) and a phase-frequency response curve (Frequency-Phase curve). The horizontal axis represents frequency in Hz (Hertz). In the amplitude-frequency response curve, the vertical axis represents amplitude in dB (decibels); in the phase-frequency response curve, the vertical axis represents phase in degrees (°).

[0085] according to Figure 6 , Figure 7 and Figure 8 It can be concluded that, compared with the scheme that only uses a PI controller, the PI controller + phase compensator control scheme of this embodiment of the invention has more stable control performance and better dynamic response when controlling the bidirectional CLLC resonant converter.

[0086] In summary, the control scheme using a PI controller and a phase compensator is advantageous because the PI controller parameters are easy to design and obtain, while the phase compensator can improve the loop phase margin, increase the loop bandwidth, and enhance the dynamic response characteristics of the CLLC converter.

[0087] Corresponding to the control method of the bidirectional CLLC resonant converter in the above embodiments, the present invention also proposes a control device for the bidirectional CLLC resonant converter.

[0088] Figure 9 This is a block diagram of the control device for a bidirectional CLLC resonant converter according to an embodiment of the present invention.

[0089] like Figure 9 As shown, the control device 100 of the bidirectional CLLC resonant converter includes: an acquisition module 110, a first input module 120, a second input module 130, and a control module 140.

[0090] The acquisition module 110 is used to acquire the actual output voltage of the bidirectional CLLC resonant converter, acquire a given voltage, and calculate the error voltage between the given voltage and the actual output voltage, wherein the given voltage is the target output voltage of the bidirectional CLLC resonant converter; the first input module 120 is used to input the error voltage into a phase compensator to obtain the output voltage of the phase compensator; the second input module 130 is used to input the output voltage of the phase compensator into a PI controller for voltage closed-loop control with frequency as the control quantity to obtain the target operating frequency of the bidirectional CLLC resonant converter in the next control cycle; the control module 140 is used to control the bidirectional CLLC resonant converter according to the target operating frequency.

[0091] In one embodiment, the compensation formula for the phase compensator is:

[0092]

[0093] Among them, f z f is the frequency corresponding to the zero point in the phase compensator. p The frequency corresponding to the pole in the phase compensator.

[0094] In one embodiment, the control device 100 of the bidirectional CLLC resonant converter further includes a first calculation module for calculating the frequency corresponding to the zeros and the frequency corresponding to the poles in the phase compensator according to the following formula:

[0095] f z =1.15f mr

[0096] f p =10f mr

[0097] Among them, f mr This is the characteristic frequency of the loop.

[0098] In one embodiment, the control device 100 of the bidirectional CLLC resonant converter further includes a second calculation module for calculating the loop characteristic frequency according to the following formula:

[0099]

[0100] Among them, L r L is the primary resonant inductor in the bidirectional CLLC resonant converter. rs C is the secondary resonant inductor in the bidirectional CLLC resonant converter. o Let n be the output capacitor in the bidirectional CLLC resonant converter, and n be the turns ratio of the transformer in the bidirectional CLLC resonant converter.

[0101] In one embodiment, the control module 140 is specifically configured to: configure the primary-side drive pulse signal of the bidirectional CLLC resonant converter according to the target operating frequency; convert the primary-side drive pulse signal into a switching transistor drive signal through the pulse drive circuit in the bidirectional CLLC resonant converter; and control the primary-side switching transistor in the bidirectional CLLC resonant converter to turn on or off using the switching transistor drive signal.

[0102] It should be noted that the specific implementation of the control device for the bidirectional CLLC resonant converter can be found in the specific implementation of the control method for the bidirectional CLLC resonant converter described above. To avoid redundancy, it will not be described in detail here.

[0103] The control device for the bidirectional CLLC resonant converter in this embodiment of the invention, through a phase compensator and a PI controller, realizes the control of the bidirectional CLLC resonant converter. It can not only improve the loop phase margin, improve the loop bandwidth, and enhance the dynamic response characteristics of the bidirectional CLLC resonant converter, but also facilitate the convenient acquisition of parameters.

[0104] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. "A plurality of" means two or more, unless otherwise explicitly specified.

[0105] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A control method for a bidirectional CLLC resonant converter, characterized in that, Includes the following steps: Obtain the actual output voltage of the bidirectional CLLC resonant converter, obtain a given voltage, and calculate the error voltage between the given voltage and the actual output voltage, wherein the given voltage is the target output voltage of the bidirectional CLLC resonant converter; The error voltage is input to the phase compensator to obtain the output voltage of the phase compensator; The output voltage of the phase compensator is input into the PI controller for closed-loop voltage control with frequency as the control quantity, so as to obtain the target operating frequency of the bidirectional CLLC resonant converter in the next control cycle. The bidirectional CLLC resonant converter is controlled according to the target operating frequency. Controlling the bidirectional CLLC resonant converter according to the target operating frequency includes: configuring the primary-side drive pulse signal of the bidirectional CLLC resonant converter according to the target operating frequency; converting the primary-side drive pulse signal into a switching transistor drive signal through a pulse drive circuit in the bidirectional CLLC resonant converter; and controlling the primary-side switching transistor in the bidirectional CLLC resonant converter to turn on or off using the switching transistor drive signal.

2. The control method for the bidirectional CLLC resonant converter according to claim 1, characterized in that, The compensation formula for the phase compensator is: in, f z The frequency corresponding to the zero point in the phase compensator. f p The frequency corresponding to the pole in the phase compensator.

3. The control method for the bidirectional CLLC resonant converter according to claim 2, characterized in that, in, The frequencies corresponding to the zeros and poles in the phase compensator are calculated using the following formulas: in, f mr This is the characteristic frequency of the loop.

4. The control method for the bidirectional CLLC resonant converter according to claim 3, characterized in that, in, The characteristic frequency of the loop is calculated using the following formula: in, L r The primary resonant inductor in the bidirectional CLLC resonant converter is... L rs This refers to the secondary resonant inductor in a bidirectional CLLC resonant converter. C o For the output capacitor of the bidirectional CLLC resonant converter, n This represents the turns ratio of the transformer in a bidirectional CLLC resonant converter.

5. A control device for a bidirectional CLLC resonant converter, characterized in that, include: The acquisition module is used to acquire the actual output voltage of the bidirectional CLLC resonant converter, acquire a given voltage, and calculate the error voltage between the given voltage and the actual output voltage, wherein the given voltage is the target output voltage of the bidirectional CLLC resonant converter; The first input module is used to input the error voltage into the phase compensator to obtain the output voltage of the phase compensator; The second input module is used to input the output voltage of the phase compensator into the PI controller for voltage closed-loop control with frequency as the control quantity, so as to obtain the target operating frequency of the bidirectional CLLC resonant converter in the next control cycle. The control module is used to control the bidirectional CLLC resonant converter according to the target operating frequency. The control module is specifically used to: configure the primary-side drive pulse signal of the bidirectional CLLC resonant converter according to the target operating frequency; convert the primary-side drive pulse signal into a switching transistor drive signal through the pulse drive circuit in the bidirectional CLLC resonant converter, and control the primary-side switching transistor in the bidirectional CLLC resonant converter to turn on or off using the switching transistor drive signal.

6. The control device for the bidirectional CLLC resonant converter according to claim 5, characterized in that, The compensation formula for the phase compensator is: in, f z The frequency corresponding to the zero point in the phase compensator. f p The frequency corresponding to the pole in the phase compensator.

7. The control device for the bidirectional CLLC resonant converter according to claim 6, characterized in that, It also includes a first calculation module for calculating the frequencies corresponding to the zeros and poles in the phase compensator according to the following formulas: in, f mr This is the characteristic frequency of the loop.

8. The control device for the bidirectional CLLC resonant converter according to claim 7, characterized in that, It also includes a second calculation module for calculating the loop characteristic frequency according to the following formula: in, L r The primary resonant inductor in the bidirectional CLLC resonant converter is... L rs This refers to the secondary resonant inductor in the bidirectional CLLC resonant converter. C o The output capacitor in the bidirectional CLLC resonant converter is... n The turns ratio of the transformer in the bidirectional CLLC resonant converter is given.

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