High-voltage quick-response adjustable switching power supply device and control method thereof

Abstract

The invention belongs to the technical field of switching power supplies, and particularly discloses a high-voltage quick-response adjustable switching power supply device and a control method thereof. The device comprises a control circuit, and a first rectifying and filtering circuit, an inverter circuit and a high-voltage side circuit which are connected in sequence, the first rectifying and filtering circuit is used for converting an input alternating-current voltage into a first direct-current voltage; the inverter circuit converts the first DC voltage into a first AC voltage at a target frequency; the high-voltage side circuit is used for boosting, rectifying and filtering the first alternating-current voltage and outputting second direct-current voltage; and the control circuit generates a feed-forward control signal based on the first direct-current voltage, the second direct-current voltage and a preset reference voltage, and adjusts the output of the inverter circuit by using the feed-forward control signal, so that the high-voltage side circuit performs output according to the preset voltage. The response speed of the power supply system to the set voltage and the load can be effectively improved, and the power supply system is simple in structure and easy to implement.

Description

Technical Field

[0001] The present application belongs to the technical field of switching power supplies, and more specifically, relates to a high-voltage fast-response adjustable switching power supply device and a control method thereof. Background Art

[0002] Compared with industrial frequency power supplies, the size and power consumption of high-voltage switching power supplies can be reduced, and the output voltage can be controlled more accurately. At present, high-frequency switching high-voltage power supplies have been widely used in fields such as industrial manufacturing, medical treatment and scientific research. In the research and preparation of ferroelectric crystals, especially lithium niobate crystals, in order to obtain uniform and controllable patterned domain reversal, it is necessary to control the waveform of the polarization high voltage, which requires the response time of the power supply to be less than the time scale of surface charge redistribution, that is, on the order of ten milliseconds; the output needs to be continuously adjustable between zero and maximum output voltage. On this basis, the ripple voltage level also needs to be controlled.

[0003] However, existing high-voltage voltage-regulated switching power supplies usually adopt a two-stage structure combining step-down regulation and fixed-ratio step-up. Due to limitations such as voltage doubling rectification, switching frequency, and ripple suppression, the power supply has a low response speed, usually only in seconds, which makes it difficult to meet the experimental requirements of ferroelectric crystal research.

[0004] Therefore, how to better improve the response speed of high-voltage switching power supplies has become a technical problem that needs to be urgently solved in the industry. Summary of the invention

[0005] In view of the defects of the prior art, the purpose of this application is to better improve the response speed of the high-voltage switching power supply, aiming to solve the problem of low response speed of the high-voltage voltage regulating switching power supply in the prior art.

[0006] To achieve the above objectives, in a first aspect, the present application provides a high-voltage fast-response adjustable switching power supply device, comprising:

[0007] A control circuit, and a first rectifying and filtering circuit, an inverter circuit and a high-voltage side circuit connected in sequence; the first rectifying and filtering circuit, the inverter circuit and the high-voltage side circuit are all connected to the control circuit;

[0008] The first rectifier and filter circuit is used to convert the input AC voltage into a first DC voltage;

[0009] The inverter circuit is used to convert the first DC voltage into a first AC voltage at a target frequency;

[0010] The high-voltage side circuit is used to perform voltage boosting, rectification and filtering on the first AC voltage to output a second DC voltage;

[0011] The control circuit is used to generate a feedforward control signal based on the first DC voltage, the second DC voltage and a preset reference voltage, and use the feedforward control signal to adjust the output of the inverter circuit so that the high-voltage side circuit outputs according to the preset voltage.

[0012] Optionally, the control circuit includes a feedforward control signal branch, a feedback control signal branch, a signal superposition module and a signal modulation module; the feedforward control signal branch and the feedback control signal branch are respectively connected to the signal superposition module, and the signal superposition module is connected to the signal modulation module;

[0013] The feedforward control signal branch is used to perform a DC gain inverse calculation based on the first DC voltage, the second DC voltage and the preset reference voltage, and perform an enhanced intermediate frequency processing on the calculated output signal to generate the feedforward control signal;

[0014] The feedback control signal branch is used to generate a feedback control signal based on the second DC voltage and a preset reference voltage;

[0015] The signal superposition module is used to perform signal superposition on the feedforward control signal and the feedback control signal to generate a superposition signal;

[0016] The signal modulation module is used to generate a PWM signal based on the superimposed signal, and use the PWM signal to control the operating state of the switch tube in the inverter circuit to adjust the output of the inverter circuit.

[0017] Optionally, the feedforward control signal branch includes a load estimation module, an inverse calculation module and a filter connected in sequence;

[0018] The load estimation module is used to determine the equivalent resistance value of the load based on the second DC voltage and the current signal output by the high-voltage side circuit;

[0019] The inverse calculation module is used to perform inverse calculation using the equivalent resistance value, the first DC voltage, the second DC voltage and the preset reference voltage to obtain a phase shift angle signal of the preset reference voltage;

[0020] The filter is used to enhance the intermediate frequency part of the phase-shift angle signal to obtain the feedforward control signal.

[0021] Optionally, the high-voltage side circuit includes a step-up transformer and a second rectifier and filter circuit connected in sequence;

[0022] The step-up transformer is used to step up the first AC voltage into a second AC voltage according to preset transformation ratio information;

[0023] The second rectifying and filtering circuit is used to rectify and filter the second AC voltage and output the second DC voltage.

[0024] Optionally, the second rectification and filtering circuit includes a rectification circuit and a filtering circuit connected in sequence; the rectification circuit is a full-wave rectification circuit, and the diodes in the full-wave rectification circuit are rectification diodes with a rated withstand voltage greater than a target voltage threshold.

[0025] Optionally, the filtering circuit includes a first capacitor, a second capacitor, a first inductor and a resistor;

[0026] One end of the first capacitor is connected to a common ground with one end of the second capacitor and a grounding end of the rectifier circuit; the other end of the first capacitor, the output end of the rectifier circuit and one end of the first inductor are connected to a common ground; the other end of the first inductor is connected to one end of the resistor; the other end of the resistor is connected to the other end of the second capacitor; the other end of the second capacitor serves as the output end of the filter circuit.

[0027] Optionally, the inverter circuit includes a full-bridge circuit and a resonant loop circuit connected in sequence;

[0028] The full-bridge circuit is used to convert the first DC voltage into a third AC voltage at a target frequency;

[0029] The resonant loop is used to perform resonance filtering on the third AC voltage and output the first AC voltage.

[0030] Optionally, the full-bridge circuit includes a first MOS transistor, a second MOS transistor, a third MOS transistor and a fourth MOS transistor; the resonant loop includes a second inductor, a third capacitor and a fourth capacitor;

[0031] The drain of the first MOS tube and the drain of the third MOS tube are connected to the output end of the first rectifying and filtering circuit, and the source of the second MOS tube and the source of the fourth MOS tube are connected to the ground end of the first rectifying and filtering circuit;

[0032] The source of the first MOS tube, the drain of the second MOS tube, and one end of the fourth capacitor are connected to the first input end of the boost transformer, the source of the third MOS tube, the drain of the fourth MOS tube, and one end of the second inductor are connected to each other, the other end of the second inductor is connected to one end of the third capacitor, and the other end of the third capacitor and the other end of the fourth capacitor are connected to the second input end of the boost transformer.

[0033] In a second aspect, the present application provides a control method for a high-voltage fast-response adjustable switching power supply device as described above, comprising:

[0034] Converting an input AC voltage into a first DC voltage;

[0035] converting the first DC voltage into a first AC voltage at a target frequency;

[0036] Performing voltage boosting, rectification and filtering processing on the first AC voltage to output a second DC voltage;

[0037] A feedforward control signal is generated based on the first DC voltage, the second DC voltage and a preset reference voltage, and the output of the inverter circuit is adjusted using the feedforward control signal so that the high-voltage side circuit outputs according to the preset voltage.

[0038] Optionally, generating a feedforward control signal based on the first DC voltage, the second DC voltage and a preset reference voltage, and adjusting the output of the inverter circuit using the feedforward control signal includes:

[0039] Performing a DC gain inverse calculation based on the first DC voltage, the second DC voltage and the preset reference voltage, and performing an enhanced intermediate frequency process on the calculated output signal to generate the feedforward control signal;

[0040] generating a feedback control signal based on the second DC voltage and a preset reference voltage;

[0041] A PWM signal is generated based on the superposition signal of the feedforward control signal and the feedback control signal, and the PWM signal is used to control the operating state of the switch tube in the inverter circuit to adjust the output of the inverter circuit.

[0042] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art:

[0043] The present application provides a high-voltage fast-response adjustable switching power supply device and a control method thereof. The device includes a control circuit, and a rectifier filter circuit, an inverter circuit and a high-voltage side circuit connected in sequence. By introducing multi-stage filtering, feedforward control and high-transformation ratio boosting, the control circuit obtains the output voltage of the rectifier filter circuit and the output voltage of the inverter circuit to generate a feedforward control signal, and performs feedforward control on the output of the inverter circuit. By real-time monitoring of the change of the input voltage, the possible fluctuation of the output voltage of the high-voltage side circuit is predicted in advance, and the high-voltage side circuit is quickly output according to the preset voltage, reducing the overshoot caused by feedback delay, which can effectively improve the response speed of the power supply system to the set voltage and load. The structure is simple and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is one of the structural schematic diagrams of a high-voltage fast-response adjustable switching power supply device provided in an embodiment of the present application;

[0045] Figure 2 This is the second structural schematic diagram of the high-voltage fast-response adjustable switching power supply device provided in the embodiment of the present application;

[0046] Figure 3 It is a structural schematic diagram of a rectifier and filter circuit in a high-voltage side circuit provided in an embodiment of the present application;

[0047] Figure 4 is a structural schematic diagram of an inverter circuit provided in an embodiment of the present application;

[0048] Figure 5 is a schematic diagram of the structure of a control circuit provided in an embodiment of the present application;

[0049] Figure 6 It is a flow chart of a control method of a high-voltage fast-response adjustable switching power supply device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] The terms "first" and "second" in the specification and claims of this application are used to distinguish different objects, rather than to describe the specific order of the objects. For example, the first rectifier and filter circuit and the second rectifier and filter circuit are used to distinguish rectifier and filter circuits with different functions, rather than to describe the specific order of the rectifier and filter circuits; for another example, the first AC voltage and the second DC voltage are used to distinguish AC voltages output by different circuits, rather than to describe the specific order of the AC voltages.

[0052] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0053] In the description of the embodiments of the present application, unless otherwise specified, the meaning of "plurality" refers to two or more than two. For example, a plurality of computer instructions refers to two or more than two computer instructions, etc.

[0054] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0055] Figure 1is one of the structural schematic diagrams of the high-voltage fast-response adjustable switching power supply device provided in the embodiment of the present application, such as Figure 1 As shown, including:

[0056] A control circuit 1, and a first rectifying and filtering circuit 2, an inverter circuit 3 and a high-voltage side circuit 4 connected in sequence; the first rectifying and filtering circuit 2, the inverter circuit 3 and the high-voltage side circuit 4 are all connected to the control circuit 1;

[0057] The first rectifier and filter circuit 2 is used to convert the input AC voltage into a first DC voltage;

[0058] The inverter circuit 3 is used to convert the first DC voltage into a first AC voltage at a target frequency;

[0059] The high-voltage side circuit 4 is used to perform voltage boosting, rectification and filtering on the first AC voltage to output a second DC voltage;

[0060] The control circuit 1 is used to generate a feedforward control signal based on the first DC voltage, the second DC voltage and a preset reference voltage, and use the feedforward control signal to adjust the output of the inverter circuit 3 so that the high-voltage side circuit 4 outputs according to the preset voltage.

[0061] Specifically, the first filtering and rectifying circuit described in the embodiment of the present application is a first-stage circuit of the device and can be used for connecting to an external power supply to filter and rectify the voltage input by the power supply to provide a signal input for a subsequent inverter circuit.

[0062] The target frequency described in the embodiment of the present application is used to characterize the signal frequency of the high-frequency AC voltage, which can be determined according to the electrical parameters of the inductor and capacitor elements used in the inverter circuit, and can be specifically set to a signal frequency in the range of 20kHz to 1MHz.

[0063] The first DC voltage described in the embodiment of the present application refers to the DC voltage obtained by filtering and rectifying the voltage input by the first filtering and rectifying circuit, which can be expressed as V i .

[0064] The first AC voltage described in the embodiment of the present application refers to an AC voltage obtained by rectifying and inverting the input first DC voltage through an inverter circuit.

[0065] The second DC voltage described in the embodiment of the present application refers to the DC voltage output by the high-voltage side circuit after boosting, rectifying and filtering the first AC voltage, which can be expressed as V o .

[0066] The preset reference voltage described in the embodiment of the present application refers to a preset DC reference voltage, which can be expressed as V ref, used to instruct the power supply device to output the DC voltage specified by the user, which can be freely adjusted and set through user instructions.

[0067] In the embodiment of the present application, the first rectifier and filter circuit 2 can adopt a full-bridge rectifier and filter circuit, and the power supply can be powered by 220V AC power. Then, the 220V low-voltage AC power supply can provide an input AC voltage to the first rectifier and filter circuit 2. After rectification and filtering, a first DC voltage V with a target amplitude can be obtained. i , such as obtaining a 300V DC bus voltage to supply the DC bus voltage to the inverter circuit 3. Optionally, when used at high power, an active power factor correction (PFC) circuit may be added to improve the circuit power factor.

[0068] In the embodiment of the present application, the first DC voltage V output by the first rectifier and filter circuit 2 is i The inverter circuit 3 can convert the first DC voltage V i The AC voltage at the target frequency is converted to obtain a first AC voltage. For example, a 300V DC bus voltage can be converted to a high-frequency AC voltage of 100kHz.

[0069] In the embodiment of the present application, the first AC voltage output by the inverter circuit 3 is transmitted to the high-voltage side circuit 4, and the high-voltage side circuit 4 can perform boosting and rectification and filtering on the first AC voltage according to a preset high-transformation ratio, for example, 1:30, to output a second DC voltage V o .

[0070] Further, in the embodiment of the present application, the first rectifying and filtering circuit 2 and the high-voltage side circuit 4 are connected to the control circuit 1, and the control circuit 1 can obtain the first DC voltage V output by the first rectifying and filtering circuit 2 through data acquisition. i And the second DC voltage V output by the high-voltage side circuit 4 o Furthermore, the control circuit 1 uses an internal feedforward control processing mechanism and a fundamental wave analysis method of the main circuit to generate a first DC voltage V i , the second DC voltage V o and preset reference voltage V ref Perform signal analysis and inverse calculation to generate feedforward control signals.

[0071] In the embodiment of the present application, a feedforward control method is introduced. The voltage feedforward control can monitor the change of the input voltage before the output voltage of the power supply changes, predict the possible fluctuation of the output voltage in advance, and adjust the control signal of the inverter circuit accordingly, so as to compensate for the influence of the input voltage change on the output voltage. This feedforward control strategy can achieve faster dynamic response, faster adjustment and smaller output voltage fluctuation.

[0072] Furthermore, in the embodiment of the present application, the control circuit 1 can use the feedforward control signal to control the operation of the switch tube device in the inverter circuit 3, adjust the output of the inverter circuit 3, and quickly make the high-voltage side circuit 4 according to the preset voltage V adjusted by the user. ref Output smoothly.

[0073] The high-voltage fast-response adjustable switching power supply device of the embodiment of the present application includes a control circuit, and a rectifier filter circuit, an inverter circuit and a high-voltage side circuit connected in sequence. By introducing multi-stage filtering, feedforward control and high-ratio transformer boosting, the control circuit is used to obtain the output voltage of the rectifier filter circuit and the output voltage of the inverter circuit to generate a feedforward control signal, and the output of the inverter circuit is feedforward controlled. By real-time monitoring of the change of the input voltage, the possible fluctuation of the output voltage of the high-voltage side circuit is predicted in advance, and the high-voltage side circuit is quickly output according to the preset voltage, reducing the overshoot caused by feedback delay, which can effectively improve the response speed of the power supply system to the set voltage and load. The structure is simple and easy to implement.

[0074] Figure 2 This is a second structural diagram of a high-voltage fast-response adjustable switching power supply device provided in an embodiment of the present application, such as Figure 2 As shown, in the embodiment of the present application, the high-voltage side circuit 4 includes a step-up transformer 41 and a second rectifier filter circuit 42 connected in sequence;

[0075] The step-up transformer 41 is used to step up the first AC voltage to a second AC voltage according to preset transformation ratio information;

[0076] The second rectifying and filtering circuit 42 is used to rectify and filter the second AC voltage and output a second DC voltage.

[0077] Specifically, the preset transformation ratio information described in the embodiment of the present application refers to the preset winding ratio information of the step-up transformer, which can be set according to actual design requirements.

[0078] The second AC voltage described in the embodiment of the present application refers to the AC voltage output after the first AC voltage is boosted by a boost transformer.

[0079] In an embodiment of the present application, the step-up transformer 41 can adopt a high-frequency high-voltage transformer, which can be specifically wound with a magnetic core of model EC70, and the transformation ratio can be set to 1:30. In order to reduce leakage inductance, the primary and secondary sides of the step-up transformer 41 are nested, and the inner skeleton is wound with the primary side and then inserted into the outer skeleton with insulation. Eight slots are set on the outer transformer skeleton, and the secondary winding is wound in slots, which has the effect of reducing distributed capacitance and improving insulation. In order to avoid sparking of the transformer and enhance heat dissipation, the transformer as a whole is vacuum-sealed with silicone.

[0080] In the embodiment of the present application, after the first AC voltage output by the inverter circuit 3 is transmitted to the step-up transformer 41 , the first AC voltage can be stepped up to a second AC voltage according to preset transformation ratio information.

[0081] Furthermore, the second rectifying and filtering circuit 42 in the high-voltage side circuit 4 rectifies and filters the second AC voltage, and converts the second AC voltage into a second DC voltage.

[0082] In the embodiment of the present application, the control circuit 1 obtains the first DC voltage V output by the first rectifier and filter circuit 2. i , the second DC voltage V output by the high-voltage side circuit 4 o and the current signal I o , and the preset reference voltage V ref Perform signal analysis and inverse calculation to generate feedforward control signals.

[0083] Furthermore, the control circuit 1 generates a control signal for controlling the operation of the inverter circuit 3 using the feedforward control signal. The control signal is given to the inverter circuit 3 to control the operation state of each switch tube device Q inside the inverter circuit 3, adjust the AC voltage outputted by the inverter circuit 3, and then quickly make the high-voltage side circuit 4 operate according to the preset voltage V ref High voltage output.

[0084] The device of the embodiment of the present application constructs a high-voltage side circuit by utilizing a step-up transformer and a rectifier filter circuit, thereby eliminating the voltage doubler rectifier circuit. Compared with the traditional voltage doubler rectifier scheme, the dynamic response speed of the power supply system can be further improved.

[0085] Figure 3 is a schematic diagram of the structure of the rectifier and filter circuit in the high-voltage side circuit provided in the embodiment of the present application, such as Figure 3 As shown, in an embodiment of the present application, the second rectifier and filter circuit 42 includes a rectifier circuit 421 and a filter circuit 422 connected in sequence; the rectifier circuit 421 is a full-wave rectifier circuit, and the diode in the full-wave rectifier circuit is a rectifier diode with a rated withstand voltage greater than the target voltage threshold.

[0086] Specifically, the target voltage threshold described in the embodiment of the present application can be determined according to the model of the high-voltage diode actually used. For example, the specific value can be 10 kV or greater.

[0087] In an embodiment of the present application, the second rectifying and filtering circuit 42 may be composed of a rectifying circuit 421 and a filtering circuit 422, wherein the rectifying circuit 421 may be a high-voltage rectifying circuit, which is composed of four high-voltage rectifying diodes, model UX-F15B, whose rated withstand voltage can reach 15kV, constituting a full-wave rectifying circuit. The rectifying circuit 421 may be used to convert the second AC voltage output by the step-up transformer 41 into a DC voltage.

[0088] Furthermore, in the embodiment of the present application, the filter circuit 422 can further filter the converted DC voltage to remove ripples and noise in the DC voltage, so as to make the output DC voltage smoother and more stable and improve the signal quality.

[0089] The device of the embodiment of the present application constructs a second rectification and filtering circuit by adopting a full-wave rectifier circuit. Compared with the voltage doubling rectifier circuit commonly used in high-voltage power supplies, the full-wave rectifier circuit does not require a voltage doubling capacitor. Combined with the high transformation ratio of the step-up transformer, the dynamic response speed of the power supply system can be further improved, thereby enhancing the power supply performance.

[0090] Continue to refer to Figure 3 Based on the above embodiment, as an optional embodiment, the filter circuit 422 includes a first capacitor C f1 , the second capacitor C f2 , the first inductor L f and resistor R f ;

[0091] The first capacitor C f1 One end of the second capacitor C f2 The first capacitor C f1 The other end of the rectifier circuit 421 and the output end of the first inductor L f The first inductor L f The other end of the resistor R f One end of the resistor R f The other end of the second capacitor C f2 The other end of the second capacitor C f2 The other end of is used as the output end of the filter circuit 422.

[0092] Specifically, in the embodiment of the present application, the filter circuit 422 can specifically adopt a CLC-II type filter circuit, wherein the first inductor L f Upper series resistor R f , used to reduce the circuit Q value and avoid self-excitation.

[0093] Among them, the filter capacitor C f1 , C f2 The specific value can be 1nF. Subject to the resonant frequency, the first inductor L f The value is 0.1H, and a 20kΩ resistor R is connected in series f To reduce the Q value.

[0094] The device of the embodiment of the present application adopts a Π-type high-voltage filter circuit and introduces an inductor, which can reduce the ripple voltage while ensuring the response speed. Compared with the common capacitor filtering in the LCC topology power supply, under the same ripple level, the CLC-Π-type filter circuit can greatly reduce the capacity requirement of the filter capacitor, thereby further improving the response speed of the power supply.

[0095] Figure 4 is a schematic diagram of the structure of the inverter circuit provided in the embodiment of the present application, such as Figure 4 As shown, in the embodiment of the present application, the inverter circuit 3 includes a full-bridge circuit 31 and a resonant loop 32 connected in sequence;

[0096] The full bridge circuit 31 is used to convert the first DC voltage into a third AC voltage at a target frequency;

[0097] The resonant loop 32 is used to perform resonance filtering on the third AC voltage and output the first AC voltage.

[0098] Specifically, in an embodiment of the present invention, the inverter circuit 3 may be composed of a full-bridge circuit 31 and a resonant loop 32, and the full-bridge circuit 31 is connected to the resonant loop 32. The full-bridge circuit 31 may convert the first DC voltage output by the first rectifier and filter circuit 2 into a third AC voltage at a target frequency. For example, the full-bridge circuit 31 may convert a DC voltage of 300 V into a high-frequency AC voltage of 100 kHz.

[0099] Furthermore, in an embodiment of the present invention, the third AC voltage is transmitted to the resonant loop 32, and the resonant loop 32 can resonate and filter the AC voltage. When the AC voltage passes through the resonant loop 32, it will resonate at the resonant frequency, so that the waveform of the output voltage is closer to a sine wave, reducing high-frequency interference and parasitic parameter oscillation, and finally outputting the first AC voltage. The resonant loop is inductive, and the current lags behind the voltage. Under heavy load, zero voltage switching can be achieved, reducing system energy consumption. Under light load and heavy load, the output second DC voltage is linearly related to the phase shift angle, and the voltage regulation dead zone is small, which is convenient for achieving precise control of the output voltage.

[0100] The device of the embodiment of the present application constructs an inverter circuit by adopting a full-bridge circuit and a resonant loop, uses the full-bridge circuit to realize the conversion from DC to AC, and improves the power transmission efficiency and reduces the harmonic content through the resonant loop, thereby realizing more efficient and stable power conversion, which is beneficial to improving the stability of the power supply system.

[0101] Continue to refer to Figure 4 Based on the above embodiment, as an optional embodiment, the full bridge circuit 31 includes a first MOS tube Q A 、The second MOS tube Q B 、The third MOS tube Q C And the fourth MOS tube Q D ; The resonant loop 32 includes a second inductor L r , the third capacitor C s and the fourth capacitor C p ;

[0102] The first MOS tube Q A The drain of the third MOS tube Q C The drain of the second MOS tube Q is connected to the output terminal of the first rectifier filter circuit 2. B The source of the fourth MOS tube Q D The source electrode is connected to the ground terminal of the first rectifier and filter circuit 2;

[0103] The first MOS tube Q A The source of the second MOS tube Q B The drain, the fourth capacitor C p One end of the third MOS tube Q is connected to the first input end of the step-up transformer 41. C The source of the fourth MOS tube Q D The drain and the second inductor L r The second inductor L r The other end of the third capacitor C s One end of the third capacitor C s The other end of the fourth capacitor C p The other end is connected in common with the second input end of the step-up transformer 41.

[0104] Specifically, in the embodiment of the present application, the high-frequency inverter circuit 3 adopts the LCC topology. Specifically, four SCT3060 silicon carbide MOSFETs are used to form the two bridge arms of the full bridge. In order to achieve zero voltage switching under heavy load, a phase shift method is adopted, and the upper and lower tubes of each bridge arm are alternately turned on. A resonant loop 32 and a high-frequency boost transformer 41 are connected in series at both ends of the bridge arm. By adopting a phase shift control LCC type resonant converter, the output voltage can be adjusted in a wide range.

[0105] In the embodiment of the present application, the second inductor Lr , the third capacitor C s and the fourth capacitor C p can be described as the resonant inductance L r , series resonant capacitor C s And the parallel resonant capacitor C p , that is, the resonant loop 32 is composed of the resonant inductor L r , series resonant capacitor C s And the parallel resonant capacitor C p Composition, among which L r and C s In series with the transformer, C p In parallel with the transformer. Taking into account the parasitic parameters and performance requirements, the switching frequency of the full-bridge circuit 31 can be set at 100kHz. p Together with the transformer secondary capacitor, it forms a parallel resonant capacitor, which can prevent the primary and secondary voltages of the high-frequency high-voltage transformer from changing suddenly, suppress the oscillation effect caused by the parasitic capacitance of the secondary diode and the primary and secondary inductance, and reduce voltage stress.

[0106] At the same time, due to the existence of the resonant loop 32, soft switching of the switch tube MOSFET can be achieved under heavy load, thereby reducing switching losses and increasing the operating frequency.

[0107] Figure 5 is a schematic diagram of the structure of the control circuit provided in the embodiment of the present application, such as Figure 5 As shown, the control circuit 1 includes a feedforward control signal branch 11, a feedback control signal branch 12, a signal superposition module 13 and a signal modulation module 14; the feedforward control signal branch 11 and the feedback control signal branch 12 are respectively connected to the signal superposition module 13, and the signal superposition module 13 is connected to the signal modulation module 14;

[0108] The feedforward control signal branch 11 is used to perform a DC gain inverse calculation based on the first DC voltage, the second DC voltage and the preset reference voltage, and perform an enhanced intermediate frequency processing on the calculated output signal to generate a feedforward control signal;

[0109] The feedback control signal branch 12 is used to generate a feedback control signal based on the second DC voltage and a preset reference voltage;

[0110] The signal superposition module 13 is used to perform signal superposition on the feedforward control signal and the feedback control signal to generate a superposition signal.

[0111] The signal modulation module 14 is used to generate a pulse width modulation (PWM) signal based on the superimposed signal, and use the PWM signal to control the operating state of the switch tube in the inverter circuit to adjust the output of the inverter circuit.

[0112] Specifically, in an embodiment of the present application, the control circuit 1 can be composed of a feedforward control signal branch 11, a feedback control signal branch 12, a signal superposition module 13 and a signal modulation module 14, the output ends of the feedforward control signal branch 11 and the feedback control signal branch 12 are respectively connected to the signal superposition module 13, and the output end of the signal superposition module 13 is connected to the signal modulation module 14.

[0113] In this embodiment, the control module of the control circuit 1 can specifically adopt digital loop control, and the core is a micro control unit of model TMS320F28377D, which has the characteristics of fast operation speed and programmable control algorithm. Through the preset sampling module, the control circuit 1 can obtain the first DC voltage V output by the first rectifier filter circuit 2 i , and the second DC voltage V output by the high-voltage side circuit 4 o and the corresponding current signal I o .

[0114] Among them, in this embodiment, the sampling module used can sample the output high voltage through a precision twin resistor and sample the output current through a low-end sampling resistor. After sampling, it is mapped to a 0-2V DC voltage and transmitted to the weak current domain through the isolation amplifier AMC1200 for feedback control. A current sampling resistor can be connected in parallel to the low end of the inverter circuit, converted into a voltage through the current detection amplifier INA296, and sent to the control board through linear optocoupler isolation for overcurrent protection.

[0115] In the embodiment of the present application, the feedforward control signal branch 11 can obtain the first DC voltage V according to the DC large signal model of the LCC circuit. i , the second DC voltage V o and preset reference voltage V ref Perform inverse calculation of the DC gain and perform intermediate frequency enhancement processing on the calculated output signal to generate a feedforward control signal.

[0116] Continue to refer to Figure 5 , based on the content of the above embodiment, as an optional embodiment, the feedforward control signal branch 11 includes a load estimation module 111, an inverse calculation module 112 and a filter 113 connected in sequence;

[0117] The load estimation module 111 is used to determine the equivalent resistance value of the load based on the second DC voltage and the current signal output by the high-voltage side circuit;

[0118] The inverse calculation module 112 is used to perform inverse calculation using the equivalent resistance value, the first DC voltage, the second DC voltage and the preset reference voltage to obtain a phase shift angle signal of the preset reference voltage;

[0119] The filter 113 is used to enhance the intermediate frequency part of the phase-shift angle signal to obtain a feedforward control signal.

[0120] Specifically, in an embodiment of the present application, the feedforward control signal branch 11 may be composed of a load estimation module 111 , an inverse calculation module 112 , and a filter 113 which are connected in sequence.

[0121] The load estimation module is used to obtain the second DC voltage V output by the high-voltage side circuit 4. o and the corresponding current signal I o , and then calculate the equivalent resistance value R of the load L .

[0122] The inverse calculation module 112 can further use the equivalent resistance value R L , the first DC voltage V i , the second DC voltage V o and preset reference voltage V ref Perform inverse calculation of DC gain and combine the fundamental wave analysis method of the main circuit to calculate the output voltage V set by the user. ref The corresponding phase shift angle is output, and the phase shift angle signal is used as the feedforward control signal θ f .

[0123] Furthermore, in order to improve the response speed, the filter 113 can use a single-pole-single-zero IIR filter to enhance the intermediate frequency processing, that is, enhance the feedforward control signal θ f That is, the intermediate frequency part of the aforementioned phase shift angle signal, thereby obtaining the feedforward control signal θ f ′.

[0124] The device of the embodiment of the present application constructs a feedforward control signal branch by utilizing a load estimation module, an inverse calculation module and an IIR filter, and adopts phase shift control. Compared with the common variable frequency control, the voltage output range of the power supply is wider and the requirements for the switching frequency are reduced; at the same time, through the feedforward control scheme of the combination of steady-state response and IIR filter, the algorithm calculation complexity is low, and the dynamic response of the power supply system is further improved, and the overshoot is reduced.

[0125] Further, in an embodiment of the present application, the feedback control signal branch 12 can be based on the acquired second DC voltage V o and preset reference voltage V ref , determine the difference between the two, and then based on the difference result, after processing by the loop compensation module, a feedback control signal θ can be generated b Among them, the loop compensation module can use a Type-I compensator, that is, a PI loop compensator.

[0126] Further, in the embodiment of the present application, the signal superposition module 13 can perform signal superposition on the aforementioned feedforward control signal and the feedback control signal to generate a superposition signal (θ f ′+θ b ), with θ f ′+θ b As the phase shift angle input of the signal modulation module 14, a one-beat lag control is performed.

[0127] Furthermore, the signal modulation module 14 adopts a PWM signal control method, based on the superimposed signal (θ f ′+θ b ) generates a corresponding PWM signal, and uses the PWM signal to control the first MOS tube Q in the inverter circuit A 、The second MOS tube Q B 、The third MOS tube Q C And the fourth MOS tube Q D The output of the inverter circuit 3 is adjusted to quickly adjust the output of the second rectifier filter circuit 42 so that it is adjusted according to the preset voltage V ref Output smoothly.

[0128] In the embodiment of the present application, the control circuit 1 adopts digital loop control, and each sampling signal is converted into a digital signal through the ADC on the DSP chip, and the PWM output of the DSP is controlled after processing. Specifically, the sampling signals of the output voltage and current of the power supply device can be sampled cycle by cycle through the built-in 16-bit ADC of the DSP. After each cycle of control is processed, the phase shift angle input of the PWM signal modulation module 14 of the next cycle is calculated by the aforementioned control algorithm to generate a control signal for driving the inverter circuit 3, and dynamically adjust the voltage output of the entire power supply device.

[0129] In a specific embodiment of the present application, the device can achieve a wide range of voltage regulation of 0-8kV and a step response time of 1ms, while the ripple is controlled at 1V.

[0130] The device of the embodiment of the present application, on the one hand, by adopting a combination of a phase-shifted controlled LCC topology, a high transformation ratio transformer and a non-voltage doubler rectification, greatly improves the dynamic response speed of the system compared to the common voltage doubler rectification scheme, realizes a wide range of voltage regulation, and reduces the influence of the parasitic capacitance of the secondary diode on the power circuit; on the other hand, compared with a linear high-voltage amplifier, its efficiency is significantly improved, the device of the embodiment of the present application has low heat generation and cost, and is easy to miniaturize.

[0131] The control method of the high-voltage fast-response adjustable switching power supply device provided in the present application is described below. The control method of the high-voltage fast-response adjustable switching power supply device described below can be referenced to each other with the high-voltage fast-response adjustable switching power supply device described above.

[0132] Figure 6 is a flow chart of a control method of a high-voltage fast-response adjustable switching power supply device provided in an embodiment of the present application, which can be applied to any of the above-mentioned high-voltage fast-response adjustable switching power supply devices such as Figure 6 As shown, the method includes:

[0133] Step S1, converting the input AC voltage into a first DC voltage;

[0134] Step S2, converting the first DC voltage into a first AC voltage at a target frequency;

[0135] Step S3, performing voltage boosting, rectification and filtering on the first AC voltage to output a second DC voltage;

[0136] Step S4, generating a feedforward control signal based on the first DC voltage, the second DC voltage and the preset reference voltage, and using the feedforward control signal to adjust the output of the inverter circuit so that the high-voltage side circuit outputs according to the preset voltage.

[0137] It can be understood that the detailed embodiments of the above method can refer to the introduction of the detailed functional implementation of each unit / module in the above device embodiment, which will not be repeated here.

[0138] It should be understood that the above method is applied to the device in the above embodiment. The implementation principle and technical effect of the method are similar to the description of the corresponding program module in the above device. The corresponding process in the method can refer to the working process of the device and will not be repeated here.

[0139] The control method of the high-voltage fast-response adjustable switching power supply device in the embodiment of the present application introduces multi-stage filtering, feedforward control and high-transformation ratio boosting, uses a control circuit to obtain the output voltage of the rectifier filter circuit and the output voltage of the inverter circuit to generate a feedforward control signal, and performs feedforward control on the output of the inverter circuit. By real-time monitoring of the change in input voltage, the possible fluctuation of the output voltage of the high-voltage side circuit is predicted in advance, and the high-voltage side circuit is quickly output according to the preset voltage, reducing the overshoot caused by feedback delay, which can effectively improve the response speed of the power supply system to the set voltage and load, and has a simple structure and is easy to implement.

[0140] Based on the content of the above embodiment, as an optional embodiment, step S4, generating a feedforward control signal based on the first DC voltage, the second DC voltage and the preset reference voltage, and using the feedforward control signal to adjust the output of the inverter circuit, includes:

[0141] Performing a DC gain inverse calculation based on the first DC voltage, the second DC voltage and the preset reference voltage, and performing an enhanced intermediate frequency processing on the calculated output signal to generate a feedforward control signal;

[0142] generating a feedback control signal based on the second DC voltage and a preset reference voltage;

[0143] A PWM signal is generated based on the superposition signal of the feedforward control signal and the feedback control signal, and the PWM signal is used to control the operating state of the switch tube in the inverter circuit to adjust the output of the inverter circuit.

[0144] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC.

[0145] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions may be transmitted from a website site, a computer, a server or a data center to another website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or a data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.

[0146] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0147] It should be understood that expressions such as "including" and "may include" that may be used in the present application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In the present application, terms such as "including" and / or "having" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0148] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the relative position relationship after connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after connection. The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only reference directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0149] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A high-voltage fast-response adjustable switching power supply device, characterized in that: include: A control circuit, and a first rectifying and filtering circuit, an inverter circuit and a high-voltage side circuit connected in sequence; the first rectifying and filtering circuit, the inverter circuit and the high-voltage side circuit are all connected to the control circuit; The first rectifier and filter circuit is used to convert the input AC voltage into a first DC voltage; The inverter circuit is used to convert the first DC voltage into a first AC voltage at a target frequency; The high-voltage side circuit is used to perform voltage boosting, rectification and filtering on the first AC voltage to output a second DC voltage; The control circuit is used to generate a feedforward control signal based on the first DC voltage, the second DC voltage and a preset reference voltage, and use the feedforward control signal to adjust the output of the inverter circuit so that the high-voltage side circuit outputs according to the preset voltage.

2. The high-voltage fast-response adjustable switching power supply device according to claim 1, characterized in that: The control circuit includes a feedforward control signal branch, a feedback control signal branch, a signal superposition module and a signal modulation module; the feedforward control signal branch and the feedback control signal branch are respectively connected to the signal superposition module, and the signal superposition module is connected to the signal modulation module; The feedforward control signal branch is used to perform a DC gain inverse calculation based on the first DC voltage, the second DC voltage and the preset reference voltage, and perform an enhanced intermediate frequency processing on the calculated output signal to generate the feedforward control signal; The feedback control signal branch is used to generate a feedback control signal based on the second DC voltage and a preset reference voltage; The signal superposition module is used to perform signal superposition on the feedforward control signal and the feedback control signal to generate a superposition signal; The signal modulation module is used to generate a PWM signal based on the superimposed signal, and use the PWM signal to control the operating state of the switch tube in the inverter circuit to adjust the output of the inverter circuit.

3. The high-voltage fast-response adjustable switching power supply device according to claim 2, characterized in that: The feedforward control signal branch includes a load estimation module, an inverse calculation module and a filter connected in sequence; The load estimation module is used to determine the equivalent resistance value of the load based on the second DC voltage and the current signal output by the high-voltage side circuit; The inverse calculation module is used to perform inverse calculation using the equivalent resistance value, the first DC voltage, the second DC voltage and the preset reference voltage to obtain a phase shift angle signal of the preset reference voltage; The filter is used to enhance the intermediate frequency part of the phase-shift angle signal to obtain the feedforward control signal.

4. The high-voltage fast-response adjustable switching power supply device according to claim 1, characterized in that: The high-voltage side circuit includes a step-up transformer and a second rectifier and filter circuit connected in sequence; The step-up transformer is used to step up the first AC voltage into a second AC voltage according to preset transformation ratio information; The second rectifying and filtering circuit is used to rectify and filter the second AC voltage and output the second DC voltage.

5. The high-voltage fast-response adjustable switching power supply device according to claim 4, characterized in that: The second rectification and filtering circuit includes a rectification circuit and a filtering circuit connected in sequence; the rectification circuit is a full-wave rectification circuit, and the diodes in the full-wave rectification circuit are rectification diodes with a rated withstand voltage greater than a target voltage threshold.

6. The high-voltage fast-response adjustable switching power supply device according to claim 5, characterized in that: The filter circuit includes a first capacitor, a second capacitor, a first inductor and a resistor; One end of the first capacitor is connected to a common ground with one end of the second capacitor and a grounding end of the rectifier circuit; the other end of the first capacitor, the output end of the rectifier circuit and one end of the first inductor are connected to a common ground; the other end of the first inductor is connected to one end of the resistor; the other end of the resistor is connected to the other end of the second capacitor; the other end of the second capacitor serves as the output end of the filter circuit.

7. The high-voltage fast-response adjustable switching power supply device according to claim 4, characterized in that: The inverter circuit comprises a full-bridge circuit and a resonant loop circuit connected in sequence; The full-bridge circuit is used to convert the first DC voltage into a third AC voltage at a target frequency; The resonant loop is used to perform resonance filtering on the third AC voltage and output the first AC voltage.

8. The high-voltage fast-response adjustable switching power supply device according to claim 7, characterized in that: The full-bridge circuit includes a first MOS tube, a second MOS tube, a third MOS tube and a fourth MOS tube; the resonant loop includes a second inductor, a third capacitor and a fourth capacitor; The drain of the first MOS tube and the drain of the third MOS tube are connected to the output end of the first rectifying and filtering circuit, and the source of the second MOS tube and the source of the fourth MOS tube are connected to the ground end of the first rectifying and filtering circuit; The source of the first MOS tube, the drain of the second MOS tube, and one end of the fourth capacitor are connected to the first input end of the boost transformer, the source of the third MOS tube, the drain of the fourth MOS tube, and one end of the second inductor are connected to each other, the other end of the second inductor is connected to one end of the third capacitor, and the other end of the third capacitor and the other end of the fourth capacitor are connected to the second input end of the boost transformer.

9. A control method for a high-voltage fast-response adjustable switching power supply device as claimed in any one of claims 1 to 8, characterized in that: include: Converting an input AC voltage into a first DC voltage; converting the first DC voltage into a first AC voltage at a target frequency; Performing voltage boosting, rectification and filtering processing on the first AC voltage to output a second DC voltage; A feedforward control signal is generated based on the first DC voltage, the second DC voltage and a preset reference voltage, and the output of the inverter circuit is adjusted using the feedforward control signal so that the high-voltage side circuit outputs according to the preset voltage.

10. The control method according to claim 9, characterized in that: The step of generating a feedforward control signal based on the first DC voltage, the second DC voltage and a preset reference voltage, and adjusting the output of the inverter circuit using the feedforward control signal comprises: Performing a DC gain inverse calculation based on the first DC voltage, the second DC voltage and the preset reference voltage to generate the feedforward control signal; generating a feedback control signal based on the second DC voltage and a preset reference voltage; A PWM signal is generated based on the superposition signal of the feedforward control signal and the feedback control signal, and the PWM signal is used to control the operating state of the switch tube in the inverter circuit to adjust the output of the inverter circuit.

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