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CN-121982959-A - Ship experiment generator set excitation loop time constant negative resistance compensation method and system

CN121982959ACN 121982959 ACN121982959 ACN 121982959ACN-121982959-A

Abstract

The invention provides a negative resistance compensation method and a negative resistance compensation system for a time constant of an excitation loop of a ship experiment generator set. And calculating and injecting a compensation voltage which is opposite to the thermal error voltage noise by the series power converter by combining the real-time current and the temperature. And performing empirical mode decomposition and Hilbert transform on the compensated current signal, analyzing the instantaneous frequency characteristic of the current signal, generating a frequency domain compensation instruction and superposing the frequency domain compensation instruction to the control signal. The gain factor of the negative resistance compensator is dynamically corrected by comparing the deviation of the ideal output of a digital reference model from the real-time current. The invention solves the technical problem that the experimental result can not accurately reflect the dynamic characteristics of a real system because of mismatching of excitation time constants caused by inconsistent physical parameters of a simulation unit and a prototype unit.

Inventors

  • ZHOU LIANGSONG
  • WU TONG

Assignees

  • 华中科技大学

Dates

Publication Date
20260505
Application Date
20260204

Claims (10)

  1. 1. The negative resistance compensation method for the time constant of the excitation loop of the ship experiment generator set is characterized by comprising the following steps of: Measuring winding data of an excitation winding of a simulation unit serving as a controlled physical object in a cold state, constructing a real-time resistance function changing along with the temperature of the winding based on the winding data, and reversely calculating a target total resistance required by the simulation unit according to a target time constant of a prototype serving as a simulation reference target; Collecting a real-time current signal and a real-time temperature of an excitation loop in the analog unit, combining the real-time current signal and the real-time temperature, and calculating thermal error voltage noise to be counteracted at the current moment based on a real-time resistance function; Generating a compensation voltage which is equal to the thermal error voltage noise in amplitude and opposite in polarity based on an active noise control principle and through a series power converter connected in an excitation loop; performing empirical mode decomposition on the real-time current signal after the compensation voltage injection to obtain a plurality of intrinsic mode function components, and analyzing the instantaneous frequency characteristics of each intrinsic mode function component by using Hilbert transformation; Generating a frequency domain compensation instruction according to the instantaneous frequency characteristic, and superposing the frequency domain compensation instruction to a control signal of the series power converter; And running a digital reference model based on prototype parameters, comparing response deviation between ideal output current and real-time current signals of the digital reference model in real time, calculating dynamic correction according to the response deviation, and correcting a gain coefficient of a negative resistance compensator in the excitation loop through the dynamic correction.
  2. 2. The method for compensating for negative resistance of exciting loop time constant of experimental ship generator set according to claim 1, wherein the measuring winding data of exciting winding of analog unit as controlled physical object in cold state, and constructing real-time resistance function according to winding temperature based on winding data, and reversely calculating target total resistance required by analog unit according to target time constant of prototype unit as analog reference target comprises the steps of: Measuring static direct current resistance and inductance parameters of an exciting winding of a simulation unit serving as a controlled physical object in a cold state by using an LCR bridge, and acquiring current data flowing through the exciting winding; calculating the internal core temperature of the exciting winding by adopting a current integral heat accumulation algorithm based on the current data; substituting the static direct current resistor, the internal core temperature and the resistance temperature coefficient of the copper conductor into a preset resistance temperature coefficient formula, and constructing to obtain a real-time resistance function changing along with the temperature of the winding; And determining the target total resistance required by the simulation unit in the experiment through ratio operation according to the inductance parameter and the target time constant of the prototype serving as the simulation reference target, and setting the target total resistance as a convergence target value of the real-time resistance function.
  3. 3. The method for compensating for negative resistance of exciting circuit time constant of marine experimental generator set according to claim 1, wherein the step of collecting real-time current signal and real-time temperature of exciting circuit in analog set, combining real-time current signal and real-time temperature and calculating thermal error voltage noise to be cancelled at present moment based on real-time resistance function comprises the following steps: collecting real-time temperature of an excitation winding and real-time current signals of an excitation loop in an analog unit; calling a real-time resistance function and calculating the actual resistance value of the exciting winding at the current moment in real time by combining the real-time temperature; Subtracting the target total resistance from the calculated actual resistance value to obtain an excess resistance value to be compensated at the current moment; and multiplying the redundant resistance value by the real-time current signal to calculate thermal error voltage noise.
  4. 4. A method of compensating for the negative resistance of the excitation loop time constant of a marine experimental generator set according to claim 3, wherein the generation of the compensation voltage having the same magnitude as the thermal error voltage noise and opposite polarity by a series power converter connected in the excitation loop based on the active noise control principle comprises the steps of: Generating an inverse offset instruction according to the thermal error voltage noise; Controlling a full-bridge power converter connected in series in an excitation loop to work in a controlled voltage source mode, and adjusting the switching duty ratio of the full-bridge power converter according to an inverted offset instruction; the driving full-bridge power converter outputs compensation voltage with the same noise amplitude as the thermal error voltage and opposite polarity; The compensation voltage is injected into the excitation loop in real time in series, and the effective port impedance of the excitation loop is clamped so as to enable the effective port impedance to be constantly maintained at the level of the target total resistance.
  5. 5. The method for compensating for the negative resistance of the excitation loop time constant of the ship experiment generator set according to claim 1, wherein the step of performing an empirical mode decomposition on the real-time current signal after the compensation voltage injection to obtain a plurality of intrinsic mode function components and analyzing the instantaneous frequency characteristics of each intrinsic mode function component by using the hilbert transform comprises the steps of: Performing empirical mode decomposition on the real-time current signal after the compensation voltage injection, and disassembling to obtain a plurality of inherent mode function components which are arranged from high frequency to low frequency; respectively executing Hilbert transformation on each separated inherent mode function component to construct an analysis signal; calculating the phase derivative of the analytic signal, and extracting the instantaneous frequency characteristic corresponding to each inherent mode function component; and constructing a time-frequency distribution map based on the instantaneous frequency characteristics, and identifying different frequency band energy distribution of the fundamental wave component, the low-frequency component and the high-frequency ripple component contained in the real-time current signal.
  6. 6. The method for compensating for negative resistance of excitation loop time constant of marine experiment generator set according to claim 5, wherein the calculating the phase derivative of the analytic signal and extracting the instantaneous frequency characteristic corresponding to each inherent mode function component comprises the following steps: Constructing a nonlinear Teager-Kaiser energy operator for frequency demodulation, and calculating to obtain an instantaneous energy distribution sequence by utilizing the nonlinear Teager-Kaiser energy operator to act on each inherent modal function component and a first-order differential signal thereof respectively; calculating absolute instantaneous frequency values of each inherent mode function component at discrete time points based on the instantaneous energy distribution sequence through energy ratio operation; and (3) applying a weighted moving average filter to the calculated absolute instantaneous frequency value, removing impulse noise caused by calculation of a truncation error, and extracting instantaneous frequency characteristics with physical smoothness.
  7. 7. The method for compensating for negative resistance of excitation loop time constant of marine experimental generator set according to claim 5, wherein generating a frequency domain compensation command according to the instantaneous frequency characteristic, and superimposing the frequency domain compensation command into the control signal of the series power converter comprises the steps of: Setting a frequency threshold value for distinguishing a dynamic response frequency band and a switching noise frequency band of the system; For fundamental and low frequency components with instantaneous frequency characteristics below a frequency threshold, maintaining full negative resistance compensation gain to ensure time constant matching; For high-frequency ripple wave components with instantaneous frequency characteristics higher than a frequency threshold, dynamically reducing negative resistance compensation gain through a preset attenuation function, or switching negative resistance polarity inversion into a positive resistance damping mode so as to inhibit self-oscillation; and generating a frequency domain compensation instruction by combining the adjustment results lower than the frequency threshold value and higher than the frequency threshold value, and superposing the frequency domain compensation instruction into a control signal of the series power converter.
  8. 8. The method for compensating for negative resistance of a time constant of an excitation loop of a ship experiment generator set according to claim 1, wherein the running is based on a digital reference model of prototype parameters, the response deviation between an ideal output current and a real-time current signal of the digital reference model is compared in real time, and a dynamic correction amount is calculated according to the response deviation, and the gain coefficient of the negative resistance compensator in the excitation loop is corrected by the dynamic correction amount, comprising the steps of: constructing a digital reference model consistent with parameters of a ship prototype generator, and inputting a voltage control instruction identical with the voltage control instruction of the simulation unit to the digital reference model; Acquiring an ideal output current output by a digital reference model and an actual exciting current of an analog unit sensor, and calculating an instantaneous response deviation between the ideal output current and the actual exciting current; Constructing a model reference control law based on a Lyapunov stability theory; Taking the instantaneous response deviation and the actual exciting current as input variables of a model reference control law, calculating the dynamic correction quantity of the gain coefficient of the negative resistance compensator by using the model reference control law, and increasing the injection quantity of the negative resistance when the actual exciting current drops faster than the ideal output current; The dynamic correction is applied to a compensation control loop where the series power converter is located, and the dynamic response track of the analog unit is forced to converge on the digital reference model so as to synthesize virtual electromagnetic inertia on a physical circuit.
  9. 9. A ship experiment generator set excitation loop time constant negative resistance compensation system, comprising a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the processor realizes the ship experiment generator set excitation loop time constant negative resistance compensation method according to any one of claims 1 to 8 when executing the computer program.
  10. 10. A computer readable storage medium having instructions stored thereon, which when executed by a processor causes the processor to be configured to perform the ship experimental genset excitation loop time constant negative resistance compensation method according to any one of claims 1 to 8.

Description

Ship experiment generator set excitation loop time constant negative resistance compensation method and system Technical Field The invention belongs to the technical field of ship power, and particularly relates to a method and a system for compensating negative resistance of a time constant of an excitation loop of a ship experiment generator set. Background The dynamic characteristics and stability of a ship power system directly relate to the overall performance of the ship, and in order to fully test and verify the dynamic behavior of the power system before the ship is built, a set of physical simulation systems are usually required to be built in a land-based laboratory. One of the core devices in the simulation system is an experimental generator set for simulating the dynamic response characteristics of a real marine generator set. When the laboratory performs physical simulation, the physical structure and rated parameters of the adopted simulation unit are limited by factors such as laboratory scale, equipment cost, purchasing period and the like, and the adopted simulation unit is difficult to completely coincide with a target large-scale generator unit in design. In particular, the differences in physical dimensions, turns, wire materials, etc. of the excitation winding can cause systematic deviations between the intrinsic time constant of the excitation loop of the analog machine set and the target time constant of the prototype machine. When the simulation unit with the mismatch of the time constants is used for dynamic experiments, the response speed and the mode of the simulation unit to disturbance are greatly different from those of a real prototype, and the experimental result loses the guiding significance on the real performance of the prototype and can not accurately expose the stability problems possibly existing in the design. Disclosure of Invention The invention provides a method and a system for compensating negative resistance of a time constant of an excitation loop of a ship experiment generator set, which are used for solving the technical problems. In a first aspect, the invention provides a method for compensating negative resistance of a time constant of an excitation loop of a ship experiment generator set, which comprises the following steps: Measuring winding data of an excitation winding of a simulation unit serving as a controlled physical object in a cold state, constructing a real-time resistance function changing along with the temperature of the winding based on the winding data, and reversely calculating a target total resistance required by the simulation unit according to a target time constant of a prototype serving as a simulation reference target; Collecting a real-time current signal and a real-time temperature of an excitation loop in the analog unit, combining the real-time current signal and the real-time temperature, and calculating thermal error voltage noise to be counteracted at the current moment based on a real-time resistance function; Generating a compensation voltage which is equal to the thermal error voltage noise in amplitude and opposite in polarity based on an active noise control principle and through a series power converter connected in an excitation loop; performing empirical mode decomposition on the real-time current signal after the compensation voltage injection to obtain a plurality of intrinsic mode function components, and analyzing the instantaneous frequency characteristics of each intrinsic mode function component by using Hilbert transformation; Generating a frequency domain compensation instruction according to the instantaneous frequency characteristic, and superposing the frequency domain compensation instruction to a control signal of the series power converter; And running a digital reference model based on prototype parameters, comparing response deviation between ideal output current and real-time current signals of the digital reference model in real time, calculating dynamic correction according to the response deviation, and correcting a gain coefficient of a negative resistance compensator in the excitation loop through the dynamic correction. Optionally, the measuring the winding data of the exciting winding of the simulation unit as the controlled physical object in a cold state, and constructing a real-time resistance function changing with the temperature of the winding based on the winding data, and reversely calculating the target total resistance required by the simulation unit according to the target time constant of the prototype unit as the simulation reference target comprises the following steps: Measuring static direct current resistance and inductance parameters of an exciting winding of a simulation unit serving as a controlled physical object in a cold state by using an LCR bridge, and acquiring current data flowing through the exciting winding; calculating the internal core temperature of the exciti