CN-121984309-A - Traceability of fluctuation to steady-state track and optimal action judgment method

CN121984309ACN 121984309 ACN121984309 ACN 121984309ACN-121984309-A

Abstract

The invention discloses a traceability and optimal action judging method of a steady-state track by wave generation, which comprises the steps of setting 9 wave generation actions of an original secondary side switching tube, determining a discrete value of a resonant cavity voltage drop V E1 corresponding to each wave generation action, judging traceability of the wave generation action, calculating an intersection point current I ins and an intersection point voltage u ins corresponding to the wave generation action, dividing a tracking time-consuming interval, determining the shortest time-consuming RANGE 1, selecting the optimal wave generation action in the wave generation actions belonging to the RANGE 1, triggering the optimal wave generation action, taking a final resonant capacitor voltage V CrF after a pulse skipping period is ended as an initial resonant capacitor voltage, calculating the phase angle of the first intersection point of the wave generation track and the steady-state track, determining the duration of the positive and negative half periods of the first pulse, enabling a converter to enter the steady-state track in the first pulse, and eliminating transient current peaks.

Inventors

ZHOU XIANG
SONG ZIHAO
WANG JUNJIE
WANG LAILI

Assignees

西安交通大学

Dates

Publication Date: 20260505
Application Date: 20260116

Claims (10)

1. A traceability and optimal action judgment method of a fluctuation to a steady-state track is characterized by comprising the following steps: Setting 9 wave-generating actions of an original secondary side switching tube, and determining the discrete value of the pressure drop V E1 of the resonant cavity corresponding to each wave-generating action; based on the discriminant and the sgn value, the traceability of the wave action is judged; Calculating intersection point current I ins and intersection point voltage u ins corresponding to the wave generating action, dividing a tracking time-consuming interval, and determining the shortest consumed time RANGE 1; In the wave-generating action belonging to RANGE 1, selecting the optimal wave-generating action by combining the stress, turn-off loss and control precision of the device; Triggering the optimal wave generating action, taking the final voltage V CrF of the resonant capacitor after the pulse skipping period is ended as the initial resonant capacitor voltage, calculating the phase angle of the first intersection point of the wave generating track and the steady-state track, determining the duration of the positive half period and the negative half period of the first pulse, enabling the converter to enter the steady-state track in the first pulse, and eliminating the transient current peak.
2. The method for judging traceability and optimal actions of fluctuation to a steady-state track according to claim 1 is characterized by further comprising the steps of obtaining current working condition parameters of a converter, selecting a target steady-state track, obtaining reference parameters of the target steady-state track, wherein the current working condition parameters comprise an input voltage V in , an output voltage V o and a final resonant capacitor voltage V CrF after a pulse skipping period is finished, and the reference parameters of the target steady-state track comprise an initial steady-state resonant current value I Lrsk , a final steady-state resonant current value I Lrsk2 , an initial steady-state resonant capacitor voltage value V Crsk , a final steady-state resonant current value V Crsk2 and a steady-state stage resonant cavity pressure drop V E2 .
3. The method for determining traceability and optimal action of the ripple on the steady-state track according to claim 1, wherein the process of setting 9 ripple actions of the primary-secondary side switching tube and determining the discrete value of the resonant cavity voltage drop V E1 corresponding to each ripple action is as follows: The first wave generating action is that a primary full-bridge first switching tube and a primary full-bridge fourth switching tube are conducted, a secondary Quan Qiaodi switching tube and a secondary Quan Qiaodi switching tube are conducted, and V E1 =V in -nV o is conducted, wherein n is the turns ratio of the primary side and the secondary side of the high-frequency transformer; The second wave generating action is that the primary full-bridge first switching tube and the primary full-bridge fourth switching tube are conducted, the secondary Quan Qiaodi two switching tubes and the secondary Quan Qiaodi three switching tubes are conducted, and V E1 =V in +nV o ; the third wave generating action is that a primary full-bridge first switching tube and a primary full-bridge fourth switching tube are conducted, a secondary side Quan Qiaodi is a switching tube, a secondary side Quan Qiaodi is a two-switching tube, or a secondary side Quan Qiaodi is a three-switching tube, and a secondary side Quan Qiaodi is a four-switching tube, and V E1 =V in is that; the fourth wave generating action is that the primary full-bridge second switching tube and the primary full-bridge third switching tube are conducted, the secondary Quan Qiaodi switching tube and the secondary Quan Qiaodi switching tube are conducted, and V E1 =-V in -nV o is formed; The fifth wave generating action is that the primary full-bridge second switching tube and the primary full-bridge third switching tube are conducted, the secondary Quan Qiaodi two switching tubes and the secondary Quan Qiaodi three switching tubes are conducted, and V E1 =-V in +nV o ; The sixth wave generating action is that the primary full-bridge second switching tube and the primary full-bridge third switching tube are conducted, the secondary side Quan Qiaodi is a switching tube, the secondary side Quan Qiaodi is a two-switching tube, or the secondary side Quan Qiaodi is a three-switching tube, and the secondary side Quan Qiaodi is a four-switching tube, and V E1 =-V in is that; The seventh wave generating action is that a primary full-bridge first switching tube, a primary full-bridge second switching tube or a primary full-bridge third switching tube and a primary full-bridge fourth switching tube are conducted, a secondary Quan Qiaodi switching tube and a secondary Quan Qiaodi switching tube are conducted, and V E1 =-nV o is set; The eighth wave generating action is that the primary full-bridge first switching tube, the primary full-bridge second switching tube or the primary full-bridge third switching tube and the primary full-bridge fourth switching tube are conducted, the secondary Quan Qiaodi two switching tubes and the secondary Quan Qiaodi three switching tubes are conducted, and V E1 =nV o ; And the ninth wave generating action is that the primary full-bridge first switching tube, the primary full-bridge second switching tube or the primary full-bridge third switching tube and the primary full-bridge fourth switching tube are conducted, the secondary side Quan Qiaodi is a switching tube, the secondary side Quan Qiaodi is a switching tube or the secondary side Quan Qiaodi is a switching tube, and the secondary side Quan Qiaodi is a switching tube, wherein V E1 =0.
4. The method for determining traceability and optimal motion of a steady-state trajectory by a hair fluctuation according to claim 1, wherein the discriminant is: Z r =sqrt(L r /C r ) is the characteristic impedance of the resonant cavity, L r is the resonant inductance value, and C r is the resonant capacitance value; The determination factor sgn is: When sgn=1, the wave action falling in the [ V E1,sol1 , V E2,sol2 ] interval is eliminated, and when sgn= -1, the wave action falling outside the [ V E1,sol1 , V E2,sol2 ] interval is eliminated, so as to form a primary traceable wave action set.
5. The method for determining traceability and optimal action of a steady-state trajectory by a wave-generating motion according to claim 1, wherein the calculation of the intersection current I ins is determined according to the position of the center of the wave-generating trajectory, specifically, I ins >0 when the center (V E1 , 0) is on the right side of the starting point (V CrF , 0), I ins <0 when the center is on the left side of the starting point, and the first-arriving intersection is preferentially selected.
6. The method of claim 1, wherein the total time of the first pulse of the optimal trajectory control is the sum of the positive half-cycle duration and the negative half-cycle duration, and the trajectory is started only in the clockwise direction from (V CrF , 0).
7. The method for determining traceability and optimal motion of a steady-state trajectory of a hair wave according to claim 1, wherein the method is used for a double active bridge resonant converter comprising a primary full bridge, a secondary full bridge, a high frequency transformer and a resonant cavity.
8. The method of claim 7, wherein the topology types of the resonant cavities include, but are not limited to, LLC resonant cavity, LCC resonant cavity, LCLC resonant cavity, CLLC resonant cavity, LC series resonant cavity and LC parallel resonant cavity.
9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor, when executing the computer program, carries out the steps of the traceability of steady-state trajectories by the fluctuation of any one of claims 1-8 and the optimal action determination method.
10. A computer readable storage medium storing a computer program, wherein the computer program when executed by a processor implements the steps of the traceability of steady-state trajectories by fluctuation and optimal action determination method of any one of claims 1-8.

Description

Traceability of fluctuation to steady-state track and optimal action judgment method Technical Field The invention belongs to the technical field of control of power electronic conversion, and relates to a traceability and optimal action judgment method of steady-state track by fluctuation. Background The double active bridge resonant converter is a core topology of medium-high power direct current conversion, and pulse cross period modulation is a key technology for realizing light load and non-unity voltage gain working condition efficiency improvement. In the pulse restarting stage of pulse cross-period modulation, the converter is driven by the fluctuation, so that a steady-state track is tracked quickly, and the transient oscillation is restrained by matching with the optimal track control. The method has the obvious defects that firstly, the selection of fluctuation is blind, a quantitative traceability judging mechanism is not available, part of actions cannot realize steady-state track tracking, secondly, the tracking time-consuming interval of the fluctuation action is not distinguished, the fastest tracking action cannot be screened out, thirdly, the unstable actions of a zero pole area and a high-slope area are not avoided, tracking failure is easily caused by small parameter deviation, thirdly, only the tracking speed is concerned, the stress and the turn-off loss of a device are not considered, and the ageing of the device is aggravated. These problems restrict the steady state response performance and service life of the converter, and cannot meet the engineering requirements of high precision and high reliability. Therefore, a determination method for achieving traceability and accurate determination of the wave-generating motion, time-consuming interval division, unstable region avoidance and multi-dimensional optimal motion screening is needed to improve the track tracing performance of the pulse restarting stage. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a method for judging the traceability and the optimal action of the wave generation motion to the steady-state track, which realizes the accurate judgment of the traceability, the time-consuming interval division, the avoidance of an unstable region and the judgment of multi-dimensional optimal action screening of the wave generation motion and improves the track tracing performance of a pulse restarting stage. In order to achieve the above object, the present invention discloses a method for determining traceability and optimal actions of a steady-state track by a fluctuation, comprising: Setting 9 wave-generating actions of an original secondary side switching tube, and determining the discrete value of the pressure drop V E1 of the resonant cavity corresponding to each wave-generating action; based on the discriminant and the sgn value, the traceability of the wave action is judged; Calculating intersection point current I ins and intersection point voltage u ins corresponding to the wave generating action, dividing a tracking time-consuming interval, and determining the shortest consumed time RANGE 1; In the wave-generating action belonging to RANGE 1, selecting the optimal wave-generating action by combining the stress, turn-off loss and control precision of the device; Triggering the optimal wave generating action, taking the final voltage V CrF of the resonant capacitor after the pulse skipping period is ended as the initial resonant capacitor voltage, calculating the phase angle of the first intersection point of the wave generating track and the steady-state track, determining the duration of the positive half period and the negative half period of the first pulse, enabling the converter to enter the steady-state track in the first pulse, and eliminating the transient current peak. The method further comprises the steps of obtaining current working condition parameters of the converter, selecting a target steady-state track, and obtaining reference parameters of the target steady-state track, wherein the current working condition parameters comprise an input voltage V in, an output voltage V o and a final resonant capacitor voltage V CrF after a pulse skipping period is finished, and the reference parameters of the target steady-state track comprise a steady-state resonant current initial value I Lrsk, a steady-state resonant current final value I Lrsk2, a steady-state resonant capacitor voltage initial value V Crsk, a steady-state resonant current final value V Crsk2 and a steady-state stage resonant cavity pressure drop V E2. Further, the process of setting 9 wave-generating actions of the primary and secondary side switching tubes and determining the discrete value of the voltage drop V E1 of the resonant cavity corresponding to each wave-generating action is as follows: The first wave generating action is that a primary full-bridge first switching tube and a primary full-br