# 用于新能源发电的新型升降压转换器及其控制策略

(广东海洋大学 电子与信息工程学院,广东 湛江 524088)

Banaei等[3]、Miao等[4]、Banaei等[5]、Li等[6]及李梦娇等[7]通过加入储能单元和开关器件获得更宽的转换比,但其输入电流不连续。交错型转换器[8]在低压应力下可以实现高升压或降压转换比,但控制策略复杂。Bahrami等[8]、Hsieh等[9]、Hasanpour等[10]及荣德生等[11]采用耦合电感结构,通过调节匝数比使电路获得更高升压比和降压比,但其开关管数量多,开关损耗大。Zhang等[12]和Kumar等[13]提出了单管的升降压转换器,在实现更宽转换比的同时,也能实现输入电流连续,但其开关管电压应力大。

## 1 转换器模态分析

Figure 1 Equivalent circuit of proposed converter

Figure 2 Key waveform diagram of the proposed converter

Figure 3 Four operation modes of the proposed converter

## 2 稳态分析和比较

### 2.1 电压转换比

VLm=Vin;

(1)

VL1=VC1+nVLm-VCo

(2)

VLm=VC1-Vin;

(3)

VL1=-VCo

(4)

(5)

(6)

(7)

Figure 4 Curve of the relationship between conversion ratio and duty cycle under different turns ratios

### 2.2 电压电流应力分析

(8)

(9)

(10)

iCo=io-iL1;

(11)

iC1=iL1=iD2

(12)

iC1=-iLm=-iD1;

(13)

iCo=iL1-io;

(14)

iD3=iL1

(15)

(io-iL1)dt+(io-iL1)dt=0⟹IL1=Io

(16)

(17)

(18)

(19)

(20)

(21)

(22)

(23)

ID1=ID2=DIo;

(24)

ID3=(1-D)Io;

(25)

(26)

(27)

(28)

(29)

(30)

(31)

### 2.4 性能对比

Table 1 Converter performance comparison

## 3 转换器控制策略

### 3.1 小信号建模

(32)

(33)

u=[vin]。

(34)

(35)

DTT时间段,根据图3(d)可以得到以下状态矩阵:

(36)

(37)

(38)

(39)

(40)

### 3.2 PI控制器设计

(41)

GClose-Loop(s)=GVod(s)Gc(s)。

(42)

Figure 5 Bode diagram of loop gain after adding PI controller

### 3.3 PI控制器结合前馈控制策略

Figure 6 Block diagram of the closed-loop control

## 4 损耗分析

(43)

(44)

(45)

(46)

### 4.2 电容损耗

(47)

(48)

PC=IC1(rms)2rC1+ICo(rms)2rCo

(49)

### 4.3 开关损耗

(50)

PS-C=Ids(rms)2rds

(51)

(52)

### 4.4 二极管损耗

(53)

(54)

(55)

PD-S=VF1ID1+VF2ID2+VF3ID3

(56)

(57)

PLoss=PL+PC+PS-C+PS-S+PD-C+PD-S

(58)

(59)

## 5 实验验证

Table 2 Parameters of the prototype

Figure 7 Physical photo of experimental prototype

Figure 8 Physical test photo

Figure 9 Experimental waveform under full load

Figure 10 Transient experimental waveform of output power

Figure 11 Transient experimental waveform of output power

Figure 12 Measured efficiency curve of the boost and buck modes

Figure 13 Calculated loss distributions in boost and buck mode under full load

## 7 结论

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# A Novel Buck-boost Converter and Its Control Strategy for New Energy Power Generation

LUO Peng, CHEN Guanghao, YANG Donghong, GUO Lei

(School of Electronic and Information Engineering, Guangdong Ocean University, Zhanjiang 524088, China)

AbstractTo solve the problem that the output voltage of the new energy power generation device varied greatly and it was difficult to realize energy storage, a novel single-switch coupled buck-boost converter based on PI controller and feed-forward control was presented. The voltage gain could be adjusted by the turns ratio of the coupled inductor, and the voltage stress on the power switch was suppressed by the passive clamped circuit with recycled leakage inductor energy. Compared with traditional buck-boost converter, the proposed converter had the advantages of wider voltage conversion ratio, continuous input current, and low voltage stress on power switch. Combing PI controller with feedforward control strategy, superior input transient response of the converter during the whole input voltage range is obtained. The operating principles and steady-state characteristics of proposed converter were analyzed and derived in detail, respectively, and the performances were compared with other single-tube buck-boost converters. The small-signal model was derived, and the correctness of PI parameter design was verified by bode diagram. The design process of PI controller combined with feedforward control strategy was analyzed. Finally, an experimental prototype with a rated power of 100 W, 20 V to 60 V input, and 48 V output was built to verify the performance of the proposed converter in boost mode and buck mode, and the feasibility of PI controller combined with feed-forward control strategy. The measured maximum efficiencies with the boost and buck modes were 97.08% and 97.10%, respectively.

Keywordscoupled inductor; buck-boost converter; small signal model; PI controller; feedforward control

doi：10.13705/j.issn.1671-6833.2023.05.016