Optimal Dynamic PI Parameters Tuning Method for Three-Port Pulse Power Decoupling Rectifier System

Abstract

The present invention discloses an optimal dynamic PI parameter setting method for a three-port pulse power decoupling rectifier system. The optimal dynamic PI parameters of the voltage outer loop are obtained through the optimal dynamic recovery curve of the VH port decoupling capacitor voltage under the energy balance control method and the optimal control rate of the three-phase AC source input power. Ideally, for any sudden increase in load pulse frequency, the VH port decoupling capacitor can be controlled to complete a discharge and charging process by increasing and decreasing the three-phase AC source input power once, so that the decoupling capacitor voltage returns to a steady state at the fastest speed. In the parameter optimization process, the present invention takes into account the influence of the pulse load on the decoupling capacitor voltage, designs the voltage outer loop PI parameters in the dynamic process of the system, so that the VH port decoupling capacitor voltage quickly returns to the steady-state voltage during the dynamic process of the load pulse frequency sudden increase. The problem that the dynamic performance of the existing PI control plus current feedforward control method is not optimal after the load pulse frequency suddenly changes is solved.

Description

Technical Field

[0001] The invention relates to the technical field of pulse load power supply, and mainly to an optimal P parameter setting method for a three-port pulse power decoupling rectifier system. Background Art

[0002] In recent years, new radars have been widely used in airborne, ship and ground equipment systems. The radar transceiver components require much higher power in the transmitting state than in the receiving state, which makes them show strong pulse load characteristics; the load peak power can even reach 10 times its average power; the load pulse operating frequency is low and not fixed, usually a few Hz to tens of Hz, and the load pulse starts and stops quickly. The above characteristics make it difficult for traditional electromechanical control to respond to changes in pulse load power in a timely manner. The strong pulse characteristics cause a series of problems such as harmonic current pollution, voltage fluctuations and flicker to the power supply system.

[0003] When pulse loads such as new radars are working, their working characteristics such as pulse frequency may change. The traditional PI control has poor dynamic performance, which will affect the performance of the system and even trigger protection to make it lose its working ability. In order to improve its dynamic performance, the literature "Wu Hongfei, Zhu Jianxin, Chen Junyu, Li Lin, Hua Ming, Xing Yan. Comprehensive power compensator for three-phase AC power supply system with high peak-to-average power ratio and low-frequency pulse load [J]. Proceedings of the CSEE, 2020, 40(13): 4310-4319." proposed a control method with pulse detection and current feedforward. Its main control idea is as follows: In order to shorten the dynamic response time of the system, pulse detection and current feedforward links are added to the current control loop. First, pulse detection is used to determine whether the load frequency has changed, and then the current feedforward calculation is performed. When the pulse frequency is detected to rise, the current feedforward value is added to the input of the low-pass filter at the initial moment of the second pulse cycle after the frequency mutation. When the pulse frequency is detected to decrease, the i of the current control link is disconnected. LdH The decoupling capacitor voltage loop output is used as the current reference to keep the capacitor voltage at the maximum value V Href Then, at the beginning of the second pulse cycle after the frequency mutation, the current feedforward value is added to the input of the low-pass filter and i is restored. LdH This method can shorten the dynamic time when the pulse load frequency changes suddenly to a certain extent. This method adds current feedforward to the voltage outer loop in the system control, which improves the dynamic performance of the system to a certain extent. However, using the voltage peak as the voltage outer loop input during the dynamic process will make the system feedback slow, thereby extending the dynamic time, and the fixed outer loop PI parameters cannot meet the dynamic performance of the system after different load pulse frequency mutations, and thus cannot guarantee the optimal dynamic performance of the system during the load pulse frequency mutation process.

[0004] The documents "Energy balance control method of three-port converter with sudden reduction of pulse frequency based on power distribution, 202310300189.5", "Energy balance control method of three-port converter based on segmented control, 202310718044.7", and "Energy balance control method of three-port converter based on load pulse cycle detection and compensation, 202211614755.1" all improve the dynamic performance, but there is algorithm switching and a secondary adjustment process.

[0005] The document "Wang Yu, Xia Yuhang, Zhou Haoyu, Zhang Chenggao. An optimal dynamic PI parameter setting method for a magnetically adjustable and voltage-regulated DC generator system: Jiangsu Province, CN114094890A[P].2022-02-25" proposes an optimal dynamic PI parameter setting method for a magnetically adjustable and voltage-regulated DC generator system, which solves the corresponding optimal dynamic PI parameters by obtaining the time function relationship of the ideal optimal output voltage curve under load mutation conditions. This method can obtain a set of corresponding optimal PI parameters under any specific load mutation, so that the PI control effect is close to the capacitor charge balance control effect, and there is no secondary adjustment process. However, the above method cannot be applied to the three-port pulse power decoupling rectifier system for the following reasons:

[0006] (1) Due to the particularity of pulse loads, the optimal dynamic PI parameter optimization scheme cannot be directly applied to three-port rectifiers. The essential difference between the two is that the output port capacitor has different functions in the circuit. The output capacitor of the traditional load is used to stabilize the voltage, and its voltage value remains unchanged before and after the dynamic adjustment process; while the function of the decoupling capacitor is to balance the power difference through periodic charging and discharging. At the end of the dynamic process, its ultimate control purpose is to maintain the voltage peak unchanged. Therefore, the control point of the capacitor charge will change.

[0007] (2) In the three-port pulse power decoupling rectifier system, since the system load is a pulse load, the decoupling capacitor voltage is a pulsating voltage with a constant peak value in steady state, and due to the existence of the three-phase filter inductor, at t 0 ~t 2 During the time period, the filter inductor stores energy rapidly due to the linear increase of the d-axis current of the three-phase AC source, and the decoupling capacitor discharges; during t 2 ~t 3 During this period, the filter inductor releases energy due to the linear decrease of the d-axis current of the three-phase AC source, and the voltage across the decoupling capacitor increases due to charging. Summary of the invention

[0008] 1. Purpose of the invention

[0009] The present invention provides an optimal PI parameter setting method for a three-port pulse power decoupling rectifier system, which solves the problems that the dynamic performance of the existing PI control plus current feedforward control method is not optimal after a sudden change in the load pulse frequency, the existing capacitor charge algorithm has algorithm switching and secondary adjustment processes, and the existing PI parameter optimization scheme is not suitable for a pulse load system.

[0010] 2. Technical solution

[0011] In order to achieve the above object, the technical solution adopted by the present invention is:

[0012] An optimal dynamic PI parameter setting method for a three-port pulse power decoupling rectifier system, the three-port pulse power decoupling rectifier system comprising a three-phase AC source, a T-type three-level AC / DC converter, an embedded DC / DC converter and a pulse load; the three-phase AC source v sa 、v sb and v sc After filtering circuit L a C a , L b C b and L c C c Then it is connected to the midpoint of the T-type bridge arm; each T-type bridge arm is composed of four switch tubes, which are S a1 S a2 S a3 S a4 , S b1 S b2 S b3 S b4 and S c1 S c2 S c3 S c4 The three ports of the T-type bridge arm are connected to the ground, VL port and VH port respectively, and the VL port is connected in parallel with the output capacitor C o Then connected to the pulse load, VH port parallel decoupling capacitor C s The DC / DC converter is then connected to the pulse load; the three-phase AC source is connected to a three-phase current sensor, the T-type three-level AC / DC converter is connected to a voltage sensor, the DC / DC converter is connected to an inductor current sensor, and the pulse load is connected to a load current sensor; it is characterized in that the optimal dynamic PI parameter setting method of the three-port pulse power decoupling rectifier system takes the sudden increase of load pulse frequency as an example, and the specific steps are as follows:

[0013] Step S1, obtaining relevant data from voltage and current sensors and pulse detection links.

[0014] Step S2, according to the energy balance control concept, obtain the time function expression of the decoupling capacitor voltage curve of the VH port when the system re-enters the steady state after the load pulse frequency changes suddenly;

[0015] Step S3, according to the energy balance concept, find the ideal optimal control rate of the three-phase AC source input power after detecting the sudden change of load pulse frequency;

[0016] Step S4, according to the ideal control rate of the three-phase AC source input power, obtain the time function expression of the ideal optimal curve of the decoupling capacitor voltage at the VH port after detecting the sudden change of the load pulse frequency;

[0017] Step S5: according to the ideal control rate of the three-phase AC source input power, the optimal dynamic PI parameters of the voltage outer loop in the dynamic process are obtained.

[0018] Preferably, the specific process of step S1 is as follows:

[0019] Step S1.1: Obtain the period T before and after the sudden change of the pulse load frequency from the pulse detection link 1 、T 2 and the average load power P o1 , P o2 , assuming that the pulse load is at t = t a When the frequency increases, the pulse detection link is at t=t a +T 2 The load pulse frequency is detected to increase at the moment, and this moment is recorded as time 0, and the three-phase AC source d-axis current i at this moment is recorded. d1 And the VH port capacitor voltage value v H0 .

[0020] Step S1.2: The d-axis current value i of the three-phase AC source after the power balance calculation system re-enters the steady state d2 ;

[0021]

[0022] Where P 耗 is the system power loss, u d is the d-axis voltage of the three-phase AC source, v s is the effective value of the phase voltage of the three-phase AC source.

[0023] Preferably, the specific process of step S2 is as follows:

[0024] Step S2: Set the load pulse width to T m , the peak power and valley power of the pulse load are P m and P n According to the energy balance concept: between 0 and T mDuring the time period T, the three-phase AC source and the decoupling capacitor provide power to the pulse load together; m ~T 2 During the time period, the three-phase AC source provides power to the decoupling capacitor and the pulse load.

[0025] In 0~T m The energy balance expression for the time period can be expressed as:

[0026]

[0027] In T m ~T 2 The energy balance expression for the time period can be expressed as:

[0028]

[0029] Where V Href Given the peak voltage at the VH port, C s is the decoupling capacitor value.

[0030] The steady-state voltage of the VH port at a fixed pulse frequency is used as the given voltage of the voltage outer loop at the dynamic moment. The given voltage of the voltage outer loop in the dynamic process is v Href for:

[0031]

[0032] Preferably, the specific process of step S3 is as follows:

[0033] Step S3.1: at 0~t 2 During the time period, control S a1 =S a2 =S a3 =S a4 =0, S b1 =1, S b2 =S b3 =S b4 =0, S c1 =S c2 =S c3 =0, S c4 =1, so that the three-phase AC source d-axis current i d k 1 The rate of change increases linearly; at t 2 ~t 3 During the time period, control S a1 =S a2 =S a3 =S a4 =0, S b1 =S b2 =S b3 =0, S b4 =1, Sc1 =1, S c2 =S c3 =S c4 = 0, so that the three-phase AC source d-axis current i d With -k 2 The rate of change of decreases linearly. Then i d It can be expressed in sections as:

[0034]

[0035] Ideal time 1 and energy balance control end time t 3 It can be expressed as:

[0036]

[0037]

[0038] Step S3.2: According to the energy balance concept, during the energy balance control period, the energy provided by the AC source to the decoupling capacitor makes the VH port voltage peak compensated to the given voltage peak V Href , the energy difference ΔE can be expressed as:

[0039]

[0040] Where S A for:

[0041]

[0042] S B +S C It can be expressed as:

[0043]

[0044] From this we can get the correlation time t 1 t 2 t 3 .

[0045] Preferably, the specific process of step S4 is as follows:

[0046] Step S4.1: Control i in the dynamic process a =0, by coordinate transformation we can get Therefore, the filter inductor obtains energy storage E in the dynamic process. L It can be expressed as:

[0047]

[0048] Where L a is the filter inductance value.

[0049] Step S4.2: According to the energy balance of the dynamic process system, the dynamic process decoupling capacitor voltage v at the VH port can be obtained. H :

[0050]

[0051] where v H0 is the capacitor voltage at the VH port at time 0.

[0052] Preferably, the specific process of step S5 is as follows:

[0053] Step S5.1: According to the steady-state voltage v of the VH port obtained in the above steps, Href , instantaneous voltage v H And the three-phase AC source d-axis current i d The corresponding optimal dynamic PI parameters can be obtained. Obtain the integral gain coefficient K in the optimal dynamic PI parameters corresponding to the sudden increase in load pulse frequency i . K is calculated according to the following formula: i :

[0054]

[0055] Step S5.2: Calculate the proportional gain coefficient K in the optimal dynamic PI parameter corresponding to the sudden increase in load pulse frequency p . K is calculated according to the following formula: p :

[0056]

[0057] Beneficial effects:

[0058] The present invention proposes an optimal dynamic PI parameter setting method for a three-port pulse power decoupling rectifier system considering the influence of the decoupling capacitor pulse load, that is, in the process of obtaining the PI parameters, the dynamic value of the decoupling capacitor voltage affected by the pulse load is calculated in real time to improve the PI parameter optimization accuracy. The PI parameters determined by this method can make: when a sudden increase in the load pulse frequency is detected at time 0, the input of the voltage outer loop is changed from the decoupling capacitor voltage peak value V Hm Switch to the instantaneous value of the decoupling capacitor voltage v H At the next load pulse start-up moment, the voltage outer loop switches back to the decoupling capacitor voltage peak control. This makes it so that the voltage feedback signal does not need to be updated after a pulse cycle in the dynamic process, shortens the dynamic time of the system, and does not exist in the secondary adjustment process. And the optimal dynamic PI parameter is based on energy balance control, so that the decoupling capacitor returns to the steady-state voltage under the new load pulse frequency after only one discharge and charge, and the dynamic performance of the system is close to the optimal. This solves the problem that the dynamic performance of the existing PI control plus current feedforward control method is not optimal after a sudden change in the load pulse frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 The three-port converter circuit topology provided by the present invention;

[0060] Figure 2 The optimal dynamic PI parameter setting flow chart of the three-port pulse power decoupling rectifier system provided by the present invention;

[0061] Figure 3 The voltage waveform of the VH port of the PI control method with current feedforward when the load frequency increases;

[0062] Figure 4 The voltage waveform of the VH port under the PI parameters corresponding to the document "Wang Yu, Xia Yuhang, Zhou Haoyu, Zhang Chenggao. An optimal dynamic PI parameter setting method for a magnetic and voltage-regulating DC generator system: Jiangsu Province, CN114094890A[P].2022-02-25";

[0063] Figure 5 A waveform diagram comparing the given d-axis current and the actual d-axis current output by the voltage outer loop under the dynamic optimal PI parameters provided by the present invention;

[0064] Figure 6 This is a voltage waveform diagram of the VH port when the load pulse frequency suddenly increases under the dynamic optimal PI parameters provided by the present invention. DETAILED DESCRIPTION

[0065] The present invention will be further described below in conjunction with the accompanying drawings.

[0066] An optimal dynamic PI parameter setting method for a three-port pulse power decoupling rectifier system, wherein the three-port pulse power decoupling rectifier system topology is as follows: Figure 1 As shown, it includes a three-phase AC source, a T-type three-level AC / DC converter, an embedded DC / DC converter and a pulse load; the three-phase AC source v sa 、v sb and v sc After filtering circuit L a C a , L b C b and L c C c Then it is connected to the midpoint of the T-type bridge arm; each T-type bridge arm is composed of four switch tubes, which are S a1 S a2 S a3 S a4 , S b1 S b2 S b3 S b4 and Sc1 S c2 S c3 S c4 The three ports of the T-type bridge arm are connected to the ground, VL port and VH port respectively, and the VL port is connected in parallel with the output capacitor C o Then connected to the pulse load, VH port parallel decoupling capacitor C s Then connect the DC / DC converter and then connect it to the pulse load; the three-phase AC source is connected to a three-phase current sensor, the T-type three-level AC / DC converter is connected to a voltage sensor, the DC / DC converter is connected to an inductor current sensor, and the pulse load is connected to a load current sensor.

[0067] like Figure 2 As shown, the optimal dynamic PI parameter setting method of the three-port pulse power decoupling rectifier system takes the sudden increase of load pulse frequency as an example, and the specific steps are as follows:

[0068] Step S1, obtaining relevant data through voltage and current sensors and pulse detection links;

[0069] Step S2, according to the energy balance control concept, obtain the time function expression of the decoupling capacitor voltage curve of the VH port when the system re-enters the steady state after the load pulse frequency changes suddenly;

[0070] Step S3, according to the energy balance concept, find the ideal optimal control rate of the three-phase AC source input power after detecting the sudden change of load pulse frequency;

[0071] Step S4, according to the ideal control rate of the three-phase AC source input power, obtain the time function expression of the ideal optimal curve of the decoupling capacitor voltage at the VH port after detecting the sudden change of the load pulse frequency;

[0072] Step S5: according to the ideal control rate of the three-phase AC source input power, the optimal dynamic PI parameters of the voltage outer loop in the dynamic process are obtained.

[0073] Furthermore, the specific process of steps S1, S2, S3, S4, and S5 is as follows:

[0074] Step S1.1: Obtain the period T before and after the sudden change of the pulse load frequency from the pulse detection link 1 、T 2 and the average load power P o1 , P o2 , assuming that the pulse load is at t = t a When the frequency increases, the pulse detection link is at t=t a +T 2 The load pulse frequency is detected to increase at the moment, and this moment is recorded as time 0, and the three-phase AC source d-axis current i at this moment is recorded. d1And the VH port capacitor voltage value v H0 .

[0075] Step S1.2: The d-axis current value i of the three-phase AC source after the power balance calculation system re-enters the steady state d2 ;

[0076]

[0077] Where P 耗 is the system power loss, u d is the d-axis voltage of the three-phase AC source, v s is the effective value of the phase voltage of the three-phase AC source.

[0078] Step S2: Set the load pulse width to T m , the peak power and valley power of the pulse load are P m and P n According to the energy balance concept: between 0 and T m During the time period T, the three-phase AC source and the decoupling capacitor provide power to the pulse load together; m ~T 2 During the time period, the three-phase AC source provides power to the decoupling capacitor and the pulse load.

[0079] In 0~T m The energy balance expression for the time period can be expressed as:

[0080]

[0081] In T m ~T 2 The energy balance expression for the time period can be expressed as:

[0082]

[0083] Where V Href Given the peak voltage at the VH port, C s is the decoupling capacitor value.

[0084] The steady-state voltage of the VH port at a fixed pulse frequency is used as the given voltage of the voltage outer loop at the dynamic moment. The given voltage of the voltage outer loop in the dynamic process is v Href for:

[0085]

[0086] Step S3.1: at 0~t 2 During the time period, control S a1 =S a2 =S a3 =S a4 =0, S b1 =1, Sb2 =S b3 =S b4 =0, S c1 =S c2 =S c3 =0, S c4 =1, so that the three-phase AC source d-axis current i d k 1 The rate of change increases linearly; at t 2 ~t 3 During the time period, control S a1 =S a2 =S a3 =S a4 =0, S b1 =S b2 =S b3 =0, S b4 =1, S c1 =1, S c2 =S c3 =S c4 = 0, so that the three-phase AC source d-axis current i d With -k 2 The rate of change of decreases linearly. Then i d It can be expressed in sections as:

[0087]

[0088] Ideal time 1 and energy balance control end time t 3 It can be expressed as:

[0089]

[0090] Step S3.2: According to the energy balance concept, during the energy balance control period, the energy provided by the AC source to the decoupling capacitor makes the VH port voltage peak compensated to the given voltage peak V Href , the energy difference ΔE can be expressed as:

[0091]

[0092] Where S A for:

[0093]

[0094] S B +S C It can be expressed as:

[0095]

[0096] From this we can get the correlation time t 1 t2 t 3 .

[0097] Step S4.1: Control i in the dynamic process a =0, by coordinate transformation we can get Therefore, the filter inductor obtains energy storage E in the dynamic process. L It can be expressed as:

[0098]

[0099] Where L a is the filter inductance value.

[0100] Step S4.2: According to the energy balance of the dynamic process system, the dynamic process decoupling capacitor voltage v at the VH port can be obtained. H :

[0101]

[0102] where v H0 is the capacitor voltage at the VH port at time 0.

[0103] Step S5.1: According to the steady-state voltage v of the VH port obtained in the above steps, Href , instantaneous voltage v H And the three-phase AC source d-axis current i d The corresponding optimal dynamic PI parameters can be obtained. Obtain the integral gain coefficient K in the optimal dynamic PI parameters corresponding to the sudden increase in load pulse frequency i . K is calculated according to the following formula: i :

[0104]

[0105] Step S5.2: Calculate the proportional gain coefficient K in the optimal dynamic PI parameter corresponding to the sudden increase in load pulse frequency p . K is calculated according to the following formula: p :

[0106]

[0107] like Figure 3 The figure shows the voltage waveform of the VH port when the load pulse frequency suddenly increases in the PI control method with current feedforward. Although the dynamic time is shorter than that of PI control, the input of its voltage outer loop is the peak value of the VH port voltage, and its feedback signal requires a load pulse cycle to update, so the system dynamic time is relatively long.

[0108] like Figure 4The figure shows the voltage waveform of the VH port under the PI parameters corresponding to the document "Wang Yu, Xia Yuhang, Zhou Haoyu, Zhang Chenggao. An optimal dynamic PI parameter setting method for a magnetic and voltage-regulating DC generator system: Jiangsu Province, CN114094890A[P].2022-02-25". This method optimizes the parameters when the load changes suddenly at one time and does not involve pulse loads. Since the load of the three-port pulse power decoupling rectifier system is a pulse load, this method is no longer suitable for the system, and its corresponding PI parameters will cause the system to return to a steady state after a period of oscillation.

[0109] like Figure 5 FIG. 4 is a waveform diagram showing a comparison between a given d-axis current and an actual d-axis current output by the voltage outer loop under the dynamic optimal PI parameters provided by the present invention. Figure 6 The voltage waveform of the VH port when the load pulse frequency suddenly increases under the dynamic optimal PI parameters provided by the present invention is shown. H It is calculated based on energy balance and considering the pulse characteristics of the load, so PI is more accurate, making the d-axis current of the three-phase AC source at t 0 ~t 2 The time period increases linearly, at t 2 ~t 3 The time period decreases linearly, so that the decoupling capacitor voltage is compensated at the fastest speed, the PI control effect approaches the energy balance control, and the dynamic performance approaches the optimal.

Claims

1. An optimal dynamic PI parameter setting method for a three-port pulse power decoupling rectifier system, the three-port pulse power decoupling rectifier system comprising a three-phase AC source, a T-type three-level AC / DC converter, an embedded DC / DC converter and a pulse load; the three-phase AC source v sa 、v sb and v sc After filtering circuit L a C a , L b C b and L c C c Then it is connected to the midpoint of the T-type bridge arm; each T-type bridge arm is composed of four switch tubes, which are S a1 S a2 S a3 S a4 , S b1 S b2 S b3 S b4 and S c1 S c2 S c3 S c4 The three ports of the T-type bridge arm are connected to the ground, VL port and VH port respectively, and the VL port is connected in parallel with the output capacitor C o Then connected to the pulse load, VH port parallel decoupling capacitor C s The three-phase AC source is connected to a three-phase current sensor, the T-type three-level AC / DC converter is connected to a voltage sensor, the DC / DC converter is connected to an inductor current sensor, and the pulse load is connected to a load current sensor; the characteristic is that: The specific steps of the optimal dynamic PI parameter tuning method are as follows: Step S1: Obtain the period T1, T2 and the average load power P before and after the sudden change of the pulse load frequency by the pulse detection link. o1 , P o2 , record the three-phase AC source d-axis current i when the load pulse frequency mutation is detected d1 And the VH port capacitor voltage value v H0 , and the d-axis current value i of the three-phase AC source after the power balance calculation system re-enters the steady state d2 Relevant data is obtained through voltage and current sensors and pulse detection links; Step S2, according to the energy balance control concept, obtain the time function expression of the decoupling capacitor voltage curve of the VH port when the system re-enters the steady state after the load pulse frequency changes suddenly; Step S3, according to the energy balance concept, obtain the ideal control rate of the three-phase AC source input power after detecting the sudden change of load pulse frequency; Step S4, according to the ideal control rate of the three-phase AC source input power, obtain the time function expression of the ideal optimal curve of the decoupling capacitor voltage at the VH port after detecting the sudden change of the load pulse frequency; Step S5, according to the ideal control rate of the three-phase AC source input power, obtaining the optimal dynamic PI parameters of the voltage outer loop in the dynamic process; The specific process of step S1 is as follows: Step S1.1: Obtain the period T1, T2 and the average load power P before and after the sudden change of the pulse load frequency by the pulse detection link. o1 , P o2 , assuming that the pulse load is at t = t a The frequency changes suddenly at the moment, so the pulse detection link is at t=t a +T2 moment detects a sudden change in load pulse frequency, records this moment as time 0, and records the three-phase AC source d-axis current i at this moment d1 And the VH port capacitor voltage value v H0 ; Step S1.2: The d-axis current value i of the three-phase AC source after the power balance calculation system re-enters the steady state d2 ; Where P 耗 is the system power loss, u d is the d-axis voltage of the three-phase AC source, v s is the effective value of the phase voltage of the three-phase AC source; The specific process of step S2 is as follows: Step S2: Set the load pulse width to T m , the peak power and valley power of the pulse load are P m and P n ; According to the energy balance concept: between 0 and T m During the time period T, the three-phase AC source and the decoupling capacitor provide power to the pulse load together; m During the time period of ~T2, the three-phase AC source provides power to the decoupling capacitor and the pulse load; In 0~T m The energy balance expression for the time period is: In T m During the time period of ~T2, the energy balance expression is expressed as: Where V Href Given the peak voltage at the VH port, C s is the decoupling capacitor value; The steady-state voltage of the VH port at a fixed pulse frequency is used as the given voltage of the dynamic process voltage outer loop. The given voltage of the dynamic process voltage outer loop is v Href for: The specific process of step S3 is as follows: Step S3.1: In the time period from 0 to t2, control S a1 =S a2 =S a3 =S a4 =0, S b1 =1, S b2 =S b3 =S b4 =0, S c1 =S c2 =S c3 =0, S c4 =1, so that the three-phase AC source d-axis current i d It increases linearly with the rate of change of k1; in the time period of t2 to t3, control S a1 =S a2 =S a3 =S a4 =0, S b1 =S b2 =S b3 =0, S b4 =1, S c1 =1, S c2 =S c3 =S c4 = 0, so that the three-phase AC source d-axis current i d It decreases linearly at a rate of -k2; then i d The segmentation is represented as: The ideal time t1 and the end time t3 of energy balance control are expressed as: Step S3.2: According to the energy balance concept, during the energy balance control period, the energy provided by the AC source to the decoupling capacitor makes the VH port voltage peak compensated to the given voltage peak V Href , the energy difference ΔE is expressed as: Where S A for: S B +S C It is expressed as: The correlation times t1, t2, and t3 are thus obtained.

2. The optimal dynamic PI parameter setting method for a three-port pulse power decoupling rectifier system according to claim 1 is characterized in that: The specific process of step S4 is as follows: Step S4.1: Control i in the dynamic process a =0, by coordinate transformation we get Therefore, the filter inductor obtains energy storage E in the dynamic process. L It is expressed as: Where L a is the filter inductance value, i a 、i b 、i c They represent the a, b, and c axis currents of the three-phase AC source respectively, and t0 represents the initial time; Step S4.2: According to the energy balance of the dynamic process system, the instantaneous voltage v at the VH port is obtained. H : where v H0 is the capacitor voltage at the VH port at time 0.

3. The optimal dynamic PI parameter setting method for a three-port pulse power decoupling rectifier system according to claim 1 is characterized in that: The specific process of step S5 is as follows: Step S5.1: According to the steady-state voltage v of the VH port obtained in the above steps, Href , instantaneous voltage v H And the three-phase AC source d-axis current i d Obtain the corresponding optimal dynamic PI parameters; obtain the integral gain coefficient K in the optimal dynamic PI parameters corresponding to the sudden increase in load pulse frequency i ; Calculate K according to the following formula i : Step S5.2: Calculate the proportional gain coefficient K in the optimal dynamic PI parameter corresponding to the sudden increase in load pulse frequency p ; Calculate K according to the following formula p :

Images