CN-121995287-A - Capacitor discharging method and system for radio frequency power amplifier and magnetic resonance equipment

CN121995287ACN 121995287 ACN121995287 ACN 121995287ACN-121995287-A

Abstract

The application discloses a capacitor discharging method and system for a radio frequency power amplifier and magnetic resonance equipment, and relates to the technical field of capacitor discharging methods. The application provides a capacitor discharging method for a radio frequency power amplifier, which comprises the steps of obtaining a voltage sequence and a current sequence of an energy storage capacitor in a preset time period, extracting voltage characteristics and current characteristics, predicting a first current value of the energy storage capacitor in a target time window according to the voltage characteristics and the current characteristics, predicting a second current value of the energy storage capacitor in the target time window according to the current resistance value of an adjustable load connected with the energy storage capacitor and the capacitance of the energy storage capacitor based on the physical rule of capacitor discharging, carrying out weighted calculation on the first current value and the second current value, obtaining a predicted current value of the energy storage capacitor in the target time window, and adjusting an execution strategy of the adjustable load according to the preset target current fluctuation range, the current real-time voltage and the predicted current value.

Inventors

YAN SHAOGANG
LI SHIHE
DU CHUN

Assignees

成都创世芯通医疗科技有限公司

Dates

Publication Date: 20260508
Application Date: 20251231

Claims (10)

1. A capacitor discharge method for a radio frequency power amplifier, comprising: Acquiring a voltage sequence and a current sequence of an energy storage capacitor in a preset time period, and extracting voltage characteristics and current characteristics; predicting a first current value of the energy storage capacitor in a target time window according to the voltage characteristic and the current characteristic; Based on a physical rule of capacitor discharge, predicting a second current value of the energy storage capacitor in a target time window according to a current resistance value of an adjustable load connected with the energy storage capacitor and a capacitance capacity of the energy storage capacitor; Weighting calculation is carried out on the first current value and the second current value, and a predicted current value of the energy storage capacitor in a target time window is obtained; And adjusting an execution strategy of the adjustable load according to the preset target current fluctuation range, the current real-time voltage and the predicted current value.
2. The capacitor discharge method for a radio frequency power amplifier according to claim 1, wherein the step of acquiring a voltage sequence and a current sequence of the energy storage capacitor in a preset time period comprises: Setting a circulation buffer zone, and continuously storing current values and voltage values corresponding to all sampling points in a latest preset time period in the circulation buffer zone to form a voltage time sequence and a current time sequence with equal length; And respectively preprocessing the voltage time sequence and the current time sequence to obtain a voltage sequence and a current sequence.
3. The capacitive discharge method for a radio frequency power amplifier according to claim 1, wherein the step of extracting the voltage characteristic and the current characteristic comprises: Performing first-order linear fitting on a voltage sequence of a preset time window, and representing the voltage dropping rate in the preset time window through the slope of a fitting straight line; Performing second-order polynomial fitting on a voltage sequence of a preset time window, and representing voltage falling acceleration through a quadratic term coefficient; acquiring an instantaneous voltage value and a voltage relative variation in a preset time window according to the voltage sequence; The voltage characteristic is characterized by at least one of an instantaneous voltage value, a voltage drop rate, and a voltage drop acceleration.
4. The capacitive discharge method for a radio frequency power amplifier according to claim 1, wherein the step of extracting the voltage characteristic and the current characteristic comprises: performing linear regression on a current sequence of a preset time window, and representing the current change rate in the preset time window by fitting a linear slope; Acquiring an instantaneous current value and a current peak value according to the current sequence; Calculating standard deviation and variation coefficient according to the current sequence of a preset time window; The current characteristic is characterized by at least one of an instantaneous current value, a current peak-to-peak value, a standard deviation, a coefficient of variation, and a current change rate.
5. The capacitor discharge method for a radio frequency power amplifier of claim 1, wherein the step of predicting a first current value of the energy storage capacitor in the target time window based on the voltage characteristic and the current characteristic comprises: Obtaining a predicted input vector according to the voltage characteristic and the current characteristic; linear fitting is carried out on the predicted input vector through a set of weights, a set of intermediate features are generated, and nonlinear transformation is carried out on the intermediate features to obtain activated features; The activation feature is mapped to a predicted scalar value by which the first current value is characterized.
6. The capacitor discharging method for a radio frequency power amplifier according to claim 1, wherein the step of predicting the second current value of the energy storage capacitor in the target time window based on the current resistance value of the adjustable load connected to the energy storage capacitor and the capacitance of the energy storage capacitor based on the physical rule of capacitor discharging comprises: And according to the voltage sequence and the current sequence in the secondary selection time period, acquiring the voltage change rate and the current value in the secondary selection time period, and calculating the capacitance of the energy storage capacitor.
7. The capacitor discharging method for a radio frequency power amplifier according to claim 1, wherein the step of predicting the second current value of the energy storage capacitor in the target time window based on the current resistance value of the adjustable load connected to the energy storage capacitor and the capacitance of the energy storage capacitor based on the physical rule of capacitor discharging comprises: taking a loop formed by the energy storage capacitor and the adjustable load as a first-order RC discharge circuit, wherein the voltage in the loop decreases exponentially along with time; taking the current moment as a time origin, taking the current voltage as an initial voltage, bringing the target future moment of a target time window into an exponential decay formula of the RC discharge circuit, obtaining a predicted voltage value of the target future moment, and obtaining a second current value based on ohm's law.
8. The capacitor discharging method for a radio frequency power amplifier according to claim 1, wherein the step of adjusting an execution strategy of the adjustable load according to a preset target current fluctuation range, a current real-time voltage and a predicted current value comprises: Calculating the prediction deviation of the predicted current value relative to the median value of the target current fluctuation range, and judging whether the adjustable load needs to be adjusted according to the prediction deviation and the prediction confidence; If the predicted current value exceeds the target current fluctuation range or the predicted deviation exceeds a preset threshold value, judging that the adjustable load needs to be adjusted; calculating a target resistance value based on ohm's law according to the target current fluctuation range, the current voltage value and the target current value; Calculating the maximum safe adjustment step length of the resistor in the adjacent control period according to the maximum change rate of the current allowed by the system and the current voltage, and calculating the resistance difference between the target resistance value and the current resistance value; If the resistance difference is smaller than the maximum safe adjustment step length, the adjustable load is adjusted to the target resistance value at one time; If the resistance difference is greater than the maximum safe adjustment step, the resistance difference is decomposed into a plurality of small steps which are not greater than the maximum safe adjustment step, an adjustment sequence is formed, and the adjustable load is adjusted to the target resistance value based on the adjustment sequence.
9. A capacitive discharge system for a radio frequency power amplifier, comprising: The characteristic extraction module is configured to acquire a voltage sequence and a current sequence of the energy storage capacitor in a preset time period and extract voltage characteristics and current characteristics; A first current value acquisition module configured to predict a first current value of the energy storage capacitor in a target time window according to the voltage characteristic and the current characteristic; the first current value acquisition module is configured to predict a second current value of the energy storage capacitor in a target time window according to the current resistance value of the adjustable load connected with the energy storage capacitor and the capacitance of the energy storage capacitor based on the physical rule of capacitor discharge; Weighting calculation is carried out on the first current value and the second current value, and a predicted current value of the energy storage capacitor in a target time window is obtained; and the execution module is configured to adjust the execution strategy of the adjustable load according to the preset target current fluctuation range, the current real-time voltage and the predicted current value.
10. A magnetic resonance apparatus comprising a capacitive discharge system for a radio frequency power amplifier as claimed in claim 9.

Description

Capacitor discharging method and system for radio frequency power amplifier and magnetic resonance equipment Technical Field The present application relates to the field of capacitor discharge methods, and in particular, to a capacitor discharge method and system for a radio frequency power amplifier, and a magnetic resonance device. Background In the field of medical equipment, medical nuclear Magnetic Resonance (MRI) technology plays a vital role, providing critical support for diagnosis and research of diseases. The rf power amplifier is used as a key component of the MRI apparatus, and generally has a larger output power, and generally has an output power of several KW to several tens KW, so as to meet the requirement of specific scanning, such as a common 3TRFM power amplifying module, where the rf power amplifier outputs 18KW. In order to meet the requirement of high-power radio frequency pulse instantaneous high current, the power supply part of the existing medical nuclear magnetic resonance radio frequency power amplifier is usually provided with an energy storage capacitor. These storage capacitors store a large amount of electrical energy during operation of the device to ensure that sufficient current is supplied at the moment of radio frequency pulse emission. However, due to the limitation of various factors such as cost and volume, the discharge flow of the discharge function circuit of the product is very small. In the production test process, after each power-down, because the energy storage capacitor discharges slowly, an operator waits for a long time until the energy storage capacitor finishes discharging, the next-stage operation can be performed, and the production efficiency is seriously affected. Disclosure of Invention The application mainly aims to provide a capacitor discharging method, a capacitor discharging system and magnetic resonance equipment for a radio frequency power amplifier, and aims to solve the technical problem that in the production test process of the existing medical nuclear magnetic resonance radio frequency power amplifier, the next stage operation can be carried out only by waiting for discharging for a long time after each power-off due to slow discharging of an energy storage capacitor of a power supply part, so that the production efficiency is affected. To achieve the above object, in a first aspect, the present application provides a capacitor discharging method for a radio frequency power amplifier, including: Acquiring a voltage sequence and a current sequence of an energy storage capacitor in a preset time period, and extracting voltage characteristics and current characteristics; predicting a first current value of the energy storage capacitor in a target time window according to the voltage characteristic and the current characteristic; Based on a physical rule of capacitor discharge, predicting a second current value of the energy storage capacitor in a target time window according to a current resistance value of an adjustable load connected with the energy storage capacitor and a capacitance capacity of the energy storage capacitor; Weighting calculation is carried out on the first current value and the second current value, and a predicted current value of the energy storage capacitor in a target time window is obtained; And adjusting an execution strategy of the adjustable load according to the preset target current fluctuation range, the current real-time voltage and the predicted current value. Optionally, the step of acquiring the voltage sequence and the current sequence of the energy storage capacitor in the preset time period includes: Setting a circulation buffer zone, and continuously storing current values and voltage values corresponding to all sampling points in a latest preset time period in the circulation buffer zone to form a voltage time sequence and a current time sequence with equal length; And respectively preprocessing the voltage time sequence and the current time sequence to obtain a voltage sequence and a current sequence. Optionally, the step of extracting the voltage characteristic and the current characteristic includes: Performing first-order linear fitting on a voltage sequence of a preset time window, and representing the voltage dropping rate in the preset time window through the slope of a fitting straight line; Performing second-order polynomial fitting on a voltage sequence of a preset time window, and representing voltage falling acceleration through a quadratic term coefficient; acquiring an instantaneous voltage value and a voltage relative variation in a preset time window according to the voltage sequence; The voltage characteristic is characterized by at least one of an instantaneous voltage value, a voltage drop rate, and a voltage drop acceleration. Optionally, the step of extracting the voltage characteristic and the current characteristic includes: performing linear regression on a current sequence of