An airborne rectifier power frequency transient control system

Abstract

The application discloses an airborne rectifier power frequency transient control system, and relates to the technical field of power supply, which comprises an alternating voltage sampling circuit, an alternating current sampling circuit, a zero-crossing detection circuit, a driving circuit and a DSP controller. When the input voltage frequency is in a steady state interval, the DSP controller works in a double closed loop PID decoupling control mode based on coordinate transformation. The DSP controller sends the calculated pulse driving signal to the power converter through the driving circuit after amplification, so that the rectifier power output voltage is kept stable. When the input voltage frequency is transient, the DSP controller superimposes input voltage feedforward control on the basis of the double closed loop PID decoupling control algorithm based on coordinate transformation, so as to improve the power grid voltage utilization rate and keep the rectifier power output voltage stable. The stable control of the output voltage is realized when the rectifier power input voltage frequency is transient due to the sudden change of the rear-end load or the sudden change of the engine speed.

Description

Technical Field

[0001] This invention relates to the field of power supply technology, specifically to an airborne rectifier power supply frequency transient control system. Background Technology

[0002] The AC voltage of the aviation power grid is mainly provided by generators, which generally have relatively small capacities. Therefore, the power grid is more susceptible to pollution when the load changes. Traditional transformer rectification technology is bulky and heavy, making it impossible to equip with sufficient redundancy equipment. Moreover, transformers generate significant noise when operating at different frequencies, causing spatial radiation interference that may interfere with other electronic equipment. Furthermore, the switching of aircraft operating modes and sudden load changes can easily cause large fluctuations in the aviation power grid, resulting in significant frequency abrupt changes that can easily cause the rectifier power supply and downstream equipment to malfunction, or even damage downstream equipment. Because transformer rectification technology, in order to adapt to the transient frequency characteristics of the aviation power grid, increases the power supply design margin and the size and weight of the equipment, it indirectly limits the aircraft's effective payload. Based on these shortcomings, this invention proposes an airborne rectifier power supply frequency transient control system. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes an airborne rectified power supply frequency transient control system.

[0004] To achieve the above objectives, an airborne rectifier power supply frequency transient control system is proposed according to an embodiment of the first aspect of the present invention, comprising an AC voltage sampling circuit, an AC current sampling circuit, a zero-crossing detection circuit, a drive circuit, and a DSP controller.

[0005] The AC voltage sampling circuit is used to acquire three-phase input voltage signals in real time, providing data for input overcurrent protection and phase-locked loop; the AC current sampling circuit is used to acquire three-phase input current signals in real time, providing data for coordinate transformation and input overcurrent protection.

[0006] The zero-crossing detection circuit is used to acquire the three-phase input voltage signal to capture the zero-crossing information of the AC signal, providing a data source for the DSP controller frequency calculation; after the DSP controller calculates the input voltage frequency, it determines whether the input voltage frequency has undergone a transient change.

[0007] If the input voltage frequency is determined to be operating in the steady-state range, i.e. no frequency transient occurs or the frequency change does not exceed the transient frequency reference value, the DSP controller operates in the coordinate transformation-based dual closed-loop PID decoupling control mode, completing the closed-loop control of the voltage outer loop and the closed-loop control of the current inner loop respectively.

[0008] If a transient change in the input voltage frequency is detected, i.e., the frequency change value exceeds the transient frequency reference value, the DSP controller determines the range of the input voltage frequency change value, and then superimposes different proportions of the input voltage feedforward value on the dual closed-loop PID decoupling control algorithm based on coordinate transformation, so that the output voltage of the rectified power supply remains stable.

[0009] Furthermore, the DSP controller is used to amplify the pulse drive signal through the drive circuit and send it to the power converter, so that the output voltage of the rectified power supply remains stable.

[0010] Furthermore, the drive circuit includes a drive transformer, independent secondary drive supply voltages, an isolation chip, a drive chip, and related resistors and capacitors;

[0011] After the DSP controller generates the pulse drive signal, it is sent to the primary input of the drive circuit through the logic chip, then to the drive chip through the isolation chip, and finally to the main power transistor drive pin in the power converter to complete the pulse drive signal transmission.

[0012] Furthermore, two transient suppression diodes are installed at both ends of the main power transistor in the power converter to suppress the positive and negative voltage spikes generated by the high-frequency drive signal during the turn-on and turn-off process of the main power transistor, ensuring that the drive voltage of the main power transistor operates within a reasonable range.

[0013] Furthermore, the specific control steps of the coordinate transformation-based dual-closed-loop PID decoupling control mode are as follows:

[0014] After processing the AC current sampling signal, it undergoes dq coordinate transformation to decouple the active and reactive components of the current in the current loop; then, PI regulation is applied to the active and reactive components respectively.

[0015] Finally, an inverse dq coordinate transformation is performed to achieve unity power factor correction of the input AC current; the AC current sampling signal is the three-phase input current signal.

[0016] The voltage loop serves as the outer control loop, used to achieve closed-loop control of the output voltage; the current loop serves as the inner control loop, used to achieve closed-loop control of the AC current; the output of the voltage loop serves as the input of the current loop to achieve dual closed-loop PID control, enabling the input current to track the input voltage in a timely manner.

[0017] Furthermore, the pulse drive signal serves as the driving source for the main power transistor in the power converter, enabling PWM pulse control of the switching transistor and maintaining stable output voltage; the power converter is used to convert the input AC voltage into the output DC voltage.

[0018] Furthermore, the output DC bus voltage can be any value within the range of 345VDC-385VDC.

[0019] Furthermore, the system also includes a filter inductor, an output soft-start circuit, an output capacitor, an output voltage sampling circuit, and an auxiliary power supply; the filter inductor is a BOOST energy storage inductor.

[0020] The output soft-start circuit is used to realize the output voltage soft-start function and suppress the starting inrush current; the output capacitor is used to realize the output voltage regulation and energy storage function; the auxiliary power supply is used to provide voltage for each functional circuit of the rectifier power supply; the output voltage sampling circuit is used to collect real-time output voltage data and provide feedback signals for voltage loop PI control.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] In this invention, when the input voltage frequency is in the steady-state range, the DSP controller operates in a coordinate transformation-based dual-closed-loop PID decoupling control mode. The DSP controller amplifies the calculated pulse drive signal through the drive circuit and sends it to the power converter, ensuring that the output voltage of the rectified power supply remains stable. When the input voltage frequency undergoes transient changes, the DSP controller superimposes input voltage feedforward control on the coordinate transformation-based dual-closed-loop PID decoupling control algorithm to improve the grid voltage utilization rate, thereby ensuring that the output voltage of the rectified power supply remains stable. This achieves stable control of the output voltage when the input voltage frequency of the rectified power supply changes due to sudden changes in the downstream load or engine speed, ensuring that the rectified power supply can operate stably and reliably under different flight modes of the aircraft and during sudden load changes, thus achieving the effect of input voltage transient control. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a system block diagram of the present invention.

[0025] Figure 2 This is a schematic diagram of the control algorithm of the present invention.

[0026] Figure 3 This is a flowchart illustrating the implementation of the present invention. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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.

[0028] like Figures 1 to 3 As shown, an airborne rectifier power supply frequency transient control system includes a filter inductor, a power converter, an output soft-start circuit, an output capacitor, an auxiliary power supply, an AC voltage sampling circuit, an AC current sampling circuit, an output voltage sampling circuit, a zero-crossing detection circuit, a drive circuit, and a DSP controller.

[0029] Among them, the filter inductor is a BOOST energy storage inductor; the power converter is used to convert the input AC voltage into the output DC voltage; when the power supply is powered on, the output soft-start circuit is used to realize the output voltage soft-start function and suppress the starting inrush current; the output capacitor is used to realize the output voltage regulation and energy storage functions; the auxiliary power supply is used to provide various voltages for the various functional circuits of the rectifier power supply.

[0030] Among them, the AC voltage sampling circuit is used to realize the input three-phase voltage sampling function, providing a data source for the input overcurrent protection function and phase-locked loop; the AC current sampling circuit realizes the input three-phase current sampling function, providing a data source for functions such as coordinate transformation and input overcurrent protection.

[0031] The output voltage sampling circuit is used to collect real-time output voltage data and provide feedback signals for the voltage loop PI control; the zero-crossing detection circuit is used to collect three-phase input voltage signals to capture AC signal zero-crossing information and provide data for the DSP controller frequency calculation.

[0032] The pulse drive signal issued by the DSP controller is converted by the drive circuit to improve the signal's driving capability and drive the main power transistor in the power converter; the DSP controller is used to implement core functions such as sampling signal processing, protection function implementation, and algorithm control.

[0033] Among them, such as Figure 1 As shown, the driving circuit of the rectified power supply is used as an example for illustration;

[0034] The drive circuit mainly consists of a drive transformer, independent secondary drive power supply voltages, isolation chips, drive chips, and related resistors and capacitors. After the DSP controller generates the drive signal, it is sent to the primary input of the drive circuit through the logic chip, then to the drive chip through the isolation chip, and finally to the main power transistor drive pin in the power converter to complete the drive signal transmission.

[0035] Meanwhile, in order to reduce the voltage spikes generated by the high-frequency drive signal during the turn-on and turn-off process of the main power transistor, two transient suppression diodes are set at both ends of the main power transistor to suppress the positive and negative voltage spike signals of the drive signal and ensure that the drive voltage of the power transistor operates within a reasonable range.

[0036] like Figure 2 As shown, the voltage loop, as the outer control loop, mainly realizes closed-loop control of the output voltage; the current loop, as the inner control loop, mainly realizes closed-loop control of the AC current; the output of the voltage loop serves as the input of the current loop to realize dual closed-loop PID control, enabling the input current to track the input voltage in a timely manner.

[0037] After the AC current sampling signal is processed, it undergoes dq coordinate transformation to decouple the active and reactive components of the current in the current loop. Then, PI regulation is performed on the active and reactive components respectively. Finally, dq coordinate inverse transformation is performed to achieve unity power factor correction of the input AC current.

[0038] When the input voltage undergoes a frequency transient, the input voltage feedforward value is superimposed on the pulse drive signal to improve the utilization rate of the input voltage and enhance the robustness of the output voltage when the input voltage frequency transients.

[0039] In the control algorithm, the AC voltage sampling signal serves as the input to the zero-crossing detection circuit and is an indirect input parameter for calculating the system's operating frequency; the AC current sampling serves as the core parameter source for coordinate transformation and the control algorithm; the output voltage sampling serves as the target parameter for the voltage outer loop control; and the pulse drive signal serves as the drive source for the power transistors of the power converter, used to implement PWM pulse control of the switching transistors and maintain stable output voltage.

[0040] like Figure 3 As shown, the working process of an airborne rectified power supply frequency transient control system is as follows:

[0041] First, real-time data of the input three-phase voltage is collected through the AC voltage sampling circuit. Then, the zero-crossing signal is collected through the zero detection circuit to capture the zero-crossing information of the AC signal, providing a data source for the frequency calculation of the DSP controller.

[0042] After calculating the input voltage frequency, if it is determined that the input voltage frequency is operating in the steady-state range, that is, no frequency transients occur or the frequency change does not exceed the transient frequency reference value, then the DSP controller will complete the closed-loop control of the voltage outer loop and the closed-loop control of the current inner loop according to the predetermined control process, so that the rectifier power supply output voltage is stable and the load operates normally at full power.

[0043] If it is determined that the input voltage frequency has a transient change, that is, the frequency change value exceeds the transient frequency reference value and enters transient mode, the DSP controller determines which range the input voltage frequency change value is in, and then superimposes different proportions of the input voltage feedforward value, thus realizing that when the input voltage frequency changes transiently, the rectifier power supply output voltage is stable and the load operates normally at full power.

[0044] In both operating modes (steady-state and transient), the DSP controller uses the input frequency calculation result as the basis for determining whether the input frequency is in steady-state or transient mode. By switching between different operating modes according to the input frequency and adjusting the input voltage feedforward value, the rectifier power supply can maintain a stable output voltage and operate normally at full power when the input voltage frequency changes transiently.

[0045] In this embodiment, the output DC bus voltage is any value within the range of 345VDC-385VDC. For example, if the initial output voltage of the output bus is 365V and the initial input voltage is 115Vac, when the input voltage frequency transiently changes to 320Hz, 360Hz, 640Hz and 800Hz, after the DSP controller superimposes the input voltage feedforward control, the rectifier power supply output voltage is stabilized, and the load operates normally at full power.

[0046] This invention patent achieves stable control of the output voltage when the input voltage frequency of an airborne three-phase rectifier power supply changes transiently, enabling the rectifier power supply to operate stably and reliably under different flight modes of the aircraft and during sudden load changes, thus achieving the effect of transient input voltage control.

[0047] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0048] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An airborne rectified power supply frequency transient control system, characterized by, The AC voltage sampling circuit, the AC current sampling circuit, the zero-crossing detection circuit, the driving circuit and the DSP controller are included. The AC voltage sampling circuit is used for collecting three-phase input voltage signals in real time, providing data sources for input overcurrent protection function and phase-locked loop; the AC current sampling circuit is used for collecting three-phase input current signals in real time, providing data sources for coordinate transformation and input overcurrent protection function; The zero-crossing detection circuit is used for obtaining three-phase input voltage signals to capture zero-crossing information of AC signals, providing data sources for frequency calculation of the DSP controller; When the DSP controller calculates the input voltage frequency, it is judged whether the input voltage frequency is transient; If the input voltage frequency is in the steady state interval, i.e. no frequency transient or the frequency change does not exceed the transient frequency reference value, the DSP controller works in the double closed-loop PID decoupling control mode based on coordinate transformation, respectively completing closed-loop control of the voltage outer ring and closed-loop control of the current inner ring; If the input voltage frequency is transient, i.e. the frequency change value exceeds the transient frequency reference value, the DSP controller judges the input voltage frequency change value in which interval, and then superimposes different proportions of input voltage feedforward value to the pulse driving signal on the basis of the double closed-loop PID decoupling control algorithm based on coordinate transformation; the DSP controller is used for sending the pulse driving signal to the power converter after amplification by the driving circuit, so that the output voltage of the rectifier power supply remains stable.

2. An airborne rectified power frequency transient control system as claimed in claim 1, wherein, The driving circuit includes a driving transformer, mutually independent secondary side driving power supply voltages, an isolation chip, a driving chip and related resistors and capacitors; After the DSP controller generates the pulse driving signal, the pulse driving signal is sent to the primary side input of the driving circuit through a logic chip, sent to the driving chip through the isolation chip, and finally sent to the main power tube driving pin in the power converter, completing the transmission of the pulse driving signal.

3. An airborne rectifier power frequency transient control system as claimed in claim 2, characterised in that, Two transient suppression diodes are arranged at both ends of the main power tube in the power converter, which are used to suppress positive and negative voltage spike signals generated by the high-frequency driving signal in the process of turning on and off of the main power tube, and ensure that the main power tube driving voltage works in a reasonable interval.

4. An airborne rectifier power frequency transient control system as claimed in claim 1, wherein, The specific control steps of the double closed-loop PID decoupling control mode based on coordinate transformation are as follows: After the AC current sampling signal is processed and dq coordinate transformation is performed, the active component and the reactive component of the current in the current loop are decoupled; then PI regulation is performed on the active component and the reactive component respectively; Finally, dq inverse transformation is performed to realize the unit power factor correction function of the input AC current; wherein the AC current sampling signal is the three-phase input current signal; The voltage loop as the control outer ring is used to realize closed-loop control of the output voltage; the current loop as the control inner ring is used to realize closed-loop control of the AC current; the output of the voltage loop is used as the input of the current loop to realize double closed-loop PID control, so that the input current can track the input voltage in time.

5. An airborne rectifier power frequency transient control system as claimed in claim 1, wherein, The pulse driving signal as the driving source of the main power tube in the power converter is used to realize PWM pulse control of the switching tube and maintain the stability of the output voltage; the power converter is used to convert the input AC voltage into output DC voltage.

6. An airborne rectifier power frequency transient control system as claimed in claim 1, wherein, The output DC bus voltage is any value in the range of 345VDC-385VDC.

7. An airborne rectifier power frequency transient control system as claimed in claim 1, wherein, The system further comprises a filter inductor, an output slow start circuit, an output capacitor, an output voltage sampling circuit and an auxiliary power supply; the filter inductor is a BOOST energy storage inductor; The output slow start circuit is used to realize the output voltage slow start function and suppress the starting impact current; the output capacitor is used to realize the output voltage stabilization and energy storage function; the auxiliary power supply is used to provide voltage for each functional circuit of the rectifier power supply; and the output voltage sampling circuit is used to collect real-time data of the output voltage and provide a feedback signal for the voltage loop PI control.

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