### Abstract

The conventional voltage source inverter is only a buck converter and conventional current source inverter is only a boost converter. By adding a Z-Source network [1], the buck-boost capability can be achieved. The recently proposed Quasi-Z-Source inverter (qZSI) [2] is an important improvement to Z-Source inverter (ZSI), which greatly reduces the passive component stress. The current-fed qZSI can buck-boost voltage and achieve bidirectional power flow without replacing the diode with an active switch [3]. It has lower current stress on inductor compared to current-fed ZSI. However, the analysis and control methods proposed in [3] are based on the assumptions that the capacitor voltage is almost constant and equal to the input voltage. These assumptions become invalid when the capacitor is very small or the lower power factor is low in some applications that the volume is a very crucial factor. The capacitor voltage has high ripple or even becomes discontinuous. In these cases, the circuit has two new operations modes except for the normal three modes, which is called discontinuous operation modes. This paper analyzes the characteristics of the discontinuous operation modes, and derives the critical conditions for these new modes under different control strategies. Simulation and experiment results are given to verify the theoretical analysis.

Original language | English (US) |
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Title of host publication | 2011 26th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2011 |

Pages | 437-441 |

Number of pages | 5 |

DOIs | |

State | Published - 2011 |

Externally published | Yes |

Event | 26th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2011 - Fort Worth, TX, United States Duration: Mar 6 2011 → Mar 10 2011 |

### Other

Other | 26th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2011 |
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Country | United States |

City | Fort Worth, TX |

Period | 3/6/11 → 3/10/11 |

### Fingerprint

### Keywords

- Continuous
- current-fed
- Discontinuous
- Maximum constant boost control
- Power factor
- Quasi-Z-Source
- SVPWM

### ASJC Scopus subject areas

- Electrical and Electronic Engineering

### Cite this

*2011 26th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2011*(pp. 437-441). [5744633] https://doi.org/10.1109/APEC.2011.5744633

**Discontinuous operation modes of current-fed Quasi-Z-Source inverter.** / Lei, Qin; Peng, Fang Z.; Yang, Shuitao.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*2011 26th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2011.*, 5744633, pp. 437-441, 26th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2011, Fort Worth, TX, United States, 3/6/11. https://doi.org/10.1109/APEC.2011.5744633

}

TY - GEN

T1 - Discontinuous operation modes of current-fed Quasi-Z-Source inverter

AU - Lei, Qin

AU - Peng, Fang Z.

AU - Yang, Shuitao

PY - 2011

Y1 - 2011

N2 - The conventional voltage source inverter is only a buck converter and conventional current source inverter is only a boost converter. By adding a Z-Source network [1], the buck-boost capability can be achieved. The recently proposed Quasi-Z-Source inverter (qZSI) [2] is an important improvement to Z-Source inverter (ZSI), which greatly reduces the passive component stress. The current-fed qZSI can buck-boost voltage and achieve bidirectional power flow without replacing the diode with an active switch [3]. It has lower current stress on inductor compared to current-fed ZSI. However, the analysis and control methods proposed in [3] are based on the assumptions that the capacitor voltage is almost constant and equal to the input voltage. These assumptions become invalid when the capacitor is very small or the lower power factor is low in some applications that the volume is a very crucial factor. The capacitor voltage has high ripple or even becomes discontinuous. In these cases, the circuit has two new operations modes except for the normal three modes, which is called discontinuous operation modes. This paper analyzes the characteristics of the discontinuous operation modes, and derives the critical conditions for these new modes under different control strategies. Simulation and experiment results are given to verify the theoretical analysis.

AB - The conventional voltage source inverter is only a buck converter and conventional current source inverter is only a boost converter. By adding a Z-Source network [1], the buck-boost capability can be achieved. The recently proposed Quasi-Z-Source inverter (qZSI) [2] is an important improvement to Z-Source inverter (ZSI), which greatly reduces the passive component stress. The current-fed qZSI can buck-boost voltage and achieve bidirectional power flow without replacing the diode with an active switch [3]. It has lower current stress on inductor compared to current-fed ZSI. However, the analysis and control methods proposed in [3] are based on the assumptions that the capacitor voltage is almost constant and equal to the input voltage. These assumptions become invalid when the capacitor is very small or the lower power factor is low in some applications that the volume is a very crucial factor. The capacitor voltage has high ripple or even becomes discontinuous. In these cases, the circuit has two new operations modes except for the normal three modes, which is called discontinuous operation modes. This paper analyzes the characteristics of the discontinuous operation modes, and derives the critical conditions for these new modes under different control strategies. Simulation and experiment results are given to verify the theoretical analysis.

KW - Continuous

KW - current-fed

KW - Discontinuous

KW - Maximum constant boost control

KW - Power factor

KW - Quasi-Z-Source

KW - SVPWM

UR - http://www.scopus.com/inward/record.url?scp=79955755267&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79955755267&partnerID=8YFLogxK

U2 - 10.1109/APEC.2011.5744633

DO - 10.1109/APEC.2011.5744633

M3 - Conference contribution

SN - 9781424480845

SP - 437

EP - 441

BT - 2011 26th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2011

ER -