CN-121984349-A - High-power electromagnetic transmitter power supply converter topology and control method thereof

CN121984349ACN 121984349 ACN121984349 ACN 121984349ACN-121984349-A

Abstract

The invention relates to a high-power electromagnetic transmitter power supply converter topology and a control method thereof. The power supply converter topology adopts a mode of combining a plurality of modules IPOS, the modules adopt a Buck+DCX-LLC cascading converter structure, each module is independently controlled through the control method, the control method comprises the steps of establishing a state space expression of the converter, obtaining an equivalent discrete mathematical model through a forward Euler formula, introducing a control time domain and a prediction time domain, establishing a prediction output equation of an equivalent circuit, introducing a disturbance observer, enabling the lumped influence of disturbance to be equivalent to load current disturbance, taking the load current disturbance as a state variable, correcting the prediction output equation, establishing an objective function and optimizing the objective function, and obtaining the optimal solution of the control quantity. The invention can realize soft switch, low-voltage input, high-voltage and high-power output, and make quick response to load change, and under the condition of disturbance, the prediction accuracy of model prediction control is improved by a disturbance observer.

Inventors

LIU NING
XI CUNGEN
DING YU
XIN SHIMIN
DENG YUJIAN
YIN ZHENKUN
LV YONGQING

Assignees

中煤科工集团上海有限公司

Dates

Publication Date: 20260505
Application Date: 20251216

Claims (10)

1. The control method of the power supply converter topology of the high-power electromagnetic transmitter is characterized in that the power supply converter topology comprises a plurality of modules, the modules are combined in a mode of input parallel connection and output serial connection, each module adopts a Buck+DCX-LLC cascade converter structure, a post-stage DCX-LLC works in a direct-current transformer state, the switching frequency is approximately equal to the resonant frequency, the transformer transformation ratio is set to be 1, the DCX-LLC is equivalent to a proportional link with the gain of 1, and each module is independently controlled by the control method; the control method comprises the following steps: step 1, selecting an inductance current of a front-stage Buck converter And output voltage Establishing a state space expression of the Buck+DCX-LLC cascade converter as a state variable; step 2, discretizing the state space expression by utilizing a forward Euler formula to obtain an equivalent discrete mathematical model; step 3, introducing two parameters of a control time domain M and a prediction time domain P, and establishing a prediction output equation of an equivalent circuit, wherein the control time domain M is the number of steps for controlling the system, and the prediction time domain P is the number of steps for predicting the output of the system; Step 4, introducing a disturbance observer, equating the lumped influence of disturbance to load current disturbance, constructing an augmented state vector by taking the load current disturbance as a third state, and correcting the predictive output equation; Step 5, establishing an objective function J of the corrected prediction output equation; And 6, optimizing the objective function J to obtain an optimal solution delta u (k) of the control quantity.
2. The control method according to claim 1, wherein the step 1 includes: The method comprises the steps of constructing state equations of on and off of a switching tube of the cascade converter, wherein the state equations are respectively as follows: 0< t < DT, equation of state under the condition that the switching tube is on: DT < T, equation of state with the switching tube off: Wherein, the Inductance for front-stage Buck converter The current C is the output filter capacitance of the front-stage Buck converter, V o is the system output voltage, V s is the system input voltage, i b is the output current of the front-stage Buck converter, D is the duty ratio of a switching tube, and T is the sampling period.
3. The control method according to claim 2, wherein the step 1 further includes: The transmission efficiency of the DCX-LLC circuit is recorded as The following steps are: So that the number of the parts to be processed, While , And (3) carrying out averaging treatment on a state equation under the condition that the switching tube is turned on and turned off by a state space averaging method to obtain a state space expression of the cascade converter: Wherein V b is the output voltage of the front-stage Buck converter, i o is the system output current, and R is the system load.
4. The control method according to claim 1, wherein the step 2 includes: converting the state space expression of the cascade converter into a discrete state equation by using an Euler forward method: Wherein, the Inductance for front-stage Buck converter V o is the system output voltage, T is the sampling period, C is the output filter capacitance of the front-stage Buck converter, For the transmission efficiency of the post-stage DCX-LLC circuit, R is a system load, V s is a system input voltage, and D is the duty ratio of a switching tube; Order the , , , Obtaining: where x (k+1) is a state variable and u (k) is a control input variable; The output voltage at the moment k is the controlled output variable y (k), and the relation between the controlled output variable y (k) and the inductor current and the capacitor voltage is as follows: In the formula, ; The resulting state space model of the cascaded converter at discrete time is represented as follows: 。
5. The control method according to claim 4, wherein the step 3 includes: Changing a state space model of the circuit under discrete time into an incremental model: Wherein, the , ; Introducing two parameters of the control time domain M and the prediction time domain P; predicting the state of the cascade converter at the time of k+1 to k+P by an incremental model, and marking the state as delta x (k+i|k), wherein i is more than or equal to 1 and less than or equal to P; predicting to obtain the state of an output equation y (k) at the moment from k+1 to k+P, and marking the state as y (k+i|k), wherein i is more than or equal to 1 and less than or equal to P; The expression defining the P-step prediction output vector Y (k+ 1|k) is expressed as follows: Definition of M-step input vector The U (k) expression is represented as follows: the system of equations of the output equation at times k+1 to k+P is converted into the following expression: in the formula, I is a constant vector, and the expressions of the G and H matrices are as follows: 。
6. the control method according to claim 1, wherein the step 4 includes: Equivalent the lumped effect of the disturbance as a load current disturbance d (k) =Δi o (k), build an augmented state vector by taking d (k) as the third state , wherein, Inductance for front-stage Buck converter V o is the system output voltage; establishing an augmented discrete state space model as , wherein, U (k) is the control input variable, y (k) is the controlled output variable, B d,d is the disturbance influence matrix, , , T is the sampling period, C is the output filter capacitance of the front-stage Buck converter, For the transmission efficiency of the post-stage DCX-LLC circuit, R is the system load, and V s is the system input voltage; based on the augmented discrete state space model, the observer equation is designed as , wherein, For the estimated value of the augmentation state, L obs is an observer gain matrix, and the gain matrix L obs is designed by a pole allocation method; Extracting disturbance values from augmented state estimates ; Introducing disturbance estimation value into original state space expression Obtaining the corrected state space expression as Wherein x (k) is a state variable; Estimating disturbance Integrating the obtained result into a prediction output equation to obtain a corrected prediction output equation as follows Wherein Y (k+ 1|k) is the P-step prediction output vector, , U (k) is an M-step input vector, I is a constant vector, F d is a disturbance accumulation effect matrix, For the perturbation sequence, the expression of the G and H matrices is as follows: 。
7. the control method according to claim 1, wherein in the step 5, the objective function J is: Wherein Q is an output deviation weight matrix, R is a control weight matrix, For the adaptive weight matrix, W (k+1) is the reference input sequence, Y (k+ 1|k) is the P-step predicted output vector, U (k) is an M-step input vector, Is a perturbation sequence.
8. The control method according to claim 1, wherein the step 6 includes: The partial derivative is calculated for the objective function, and the partial derivative is zero, so that the optimal duty ratio sequence is obtained ; Applying the first element of the calculated open loop optimal control sequence to the system, and defining optimal control increment as follows: In the above-mentioned method, the step of, 。
9. The power supply converter topology of the high-power electromagnetic transmitter is characterized by comprising a plurality of modules, wherein each module is combined in a mode of input parallel connection and output series connection, each module adopts a Buck+DCX-LLC cascade converter structure, the latter stage DCX-LLC works in a direct-current transformer state, the switching frequency is approximately equal to the resonant frequency, the transformer transformation ratio is set to be 1, so that the DCX-LLC is equivalent to a proportional link with a gain of 1, and each module is independently controlled by the control method according to any one of claims 1-8.
10. A high-power electromagnetic transmitter is characterized in that, the high power electromagnetic transmitter using the power converter topology of claim 9.

Description

High-power electromagnetic transmitter power supply converter topology and control method thereof Technical Field The invention relates to the fields of power electronics and energy detection, in particular to a high-power electromagnetic transmitter power supply converter topology and a control method thereof. Background Currently, mineral resource demands in China are continuously increased, and energy detection technologies are also rapidly developed. In this context, electromagnetic methods have become the core means of underground and marine mineral exploration by virtue of their efficiency. The method excites an underground conductor to generate a secondary field by transmitting a primary electromagnetic field, and further analyzes the secondary field data to invert the resource distribution rule. However, existing electromagnetic detection transmitters are generally limited by transmission power, and the exploration depth is difficult to meet the increasing deep resource detection requirements. The core dc power supply of an electromagnetic transmitter must combine high power output, high efficiency and fast dynamic response capability. However, the conventional power supply system adopting PI control has the disadvantages of lag response and insufficient robustness, and is difficult to cope with complex and changeable working environments. Disclosure of Invention In view of the above, the present invention provides a high power electromagnetic transmitter power converter topology and method of controlling the same that solves or at least alleviates one or more of the above-identified problems and other problems of the prior art. In order to achieve the foregoing objective, a first aspect of the present invention provides a control method for a power supply converter topology of a high-power electromagnetic transmitter, where the power supply converter topology includes a plurality of modules, each module is combined in a mode of input parallel connection and output series connection, each module adopts a buck+dcx-LLC cascaded converter structure, a post-stage DCX-LLC operates in a dc transformer state, a switching frequency is approximately equal to a resonant frequency, a transformer transformation ratio is set to 1, the DCX-LLC is equivalent to a proportional link with a gain of 1, and each module is independently controlled by the control method; the control method comprises the following steps: step 1, selecting an inductance current of a front-stage Buck converter And output voltageEstablishing a state space expression of the Buck+DCX-LLC cascade converter as a state variable; step 2, discretizing the state space expression by utilizing a forward Euler formula to obtain an equivalent discrete mathematical model; step 3, introducing two parameters of a control time domain M and a prediction time domain P, and establishing a prediction output equation of an equivalent circuit, wherein the control time domain M is the number of steps for controlling the system, and the prediction time domain P is the number of steps for predicting the output of the system; Step 4, introducing a disturbance observer, equating the lumped influence of disturbance to load current disturbance, constructing an augmented state vector by taking the load current disturbance as a third state, and correcting the predictive output equation; Step 5, establishing an objective function J of the corrected prediction output equation; And 6, optimizing the objective function J to obtain an optimal solution delta u (k) of the control quantity. In the foregoing control method, optionally, the step 1 includes: The method comprises the steps of constructing state equations of on and off of a switching tube of the cascade converter, wherein the state equations are respectively as follows: 0< t < DT, equation of state under the condition that the switching tube is on: DT < T, equation of state with the switching tube off: Wherein, the Inductance for front-stage Buck converterThe current C is the output filter capacitance of the front-stage Buck converter, V o is the system output voltage, V s is the system input voltage, i b is the output current of the front-stage Buck converter, D is the duty ratio of a switching tube, and T is the sampling period. In the foregoing control method, optionally, the step 1 further includes: The transmission efficiency of the DCX-LLC circuit is recorded as The following steps are: So that the number of the parts to be processed, While, And (3) carrying out averaging treatment on a state equation under the condition that the switching tube is turned on and turned off by a state space averaging method to obtain a state space expression of the cascade converter: Wherein V b is the output voltage of the front-stage Buck converter, i o is the system output current, and R is the system load. In the foregoing control method, optionally, the step 2 includes: converting the state space expression of the cascade co