Single phase grid connected motor drive system with dc-link shunt compensator and small dc-link capacitor
- 1. The Master of IEEE Projects Copyright © 2016LeMenizInfotech. All rights reserved LeMenizInfotech 36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue, Pondicherry-605 005. Call: 0413-4205444, +91 9566355386, 99625 88976. Web :www.lemenizinfotech.com/ www.ieeemaster.com Mail : projects@lemenizinfotech.com Single-Phase Grid Connected Motor Drive System with DC-link Shunt Compensator and Small DC-link Capacitor Introduction: The single-phase grid-connected systems have been commonly used in various applications such as home appliances, renewable energy systems, electrical vehicle chargers, and so on. The single- phase grid basically supplies the ripple power to the load, so the system requires sufficient energy buffer to absorb this ripple power. The electrolytic capacitor is commonly used as the energy buffer, due to its large capacitance per unit volume. However, the large DC-link capacitor system requires the grid harmonic compensation circuits such as the heavy passive series filter and the cascaded boost converter in order to satisfy grid harmonic regulations, which increases cost and size of the system. Moreover, the electrolytic capacitor has high failure rate and lowers the reliability of the overall system. Existing system: Reconstructing the phase currents in a three-phase inverter using current measurements from integrated pilot current sensors placed in the three low-side inverter power switches. Although the figure shows integrated current sensors in power MOSFETs for the low-side inverter switches, past work has also demonstrated the feasibility of introducing such integrated sensors into IGBTs. Since the output phase current passes through the low-side switch for only a portion of the fundamental cycle, special steps must be taken to cope with the incomplete current feedback information. This paper demonstrates
- 2. The Master of IEEE Projects Copyright © 2016LeMenizInfotech. All rights reserved LeMenizInfotech 36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue, Pondicherry-605 005. Call: 0413-4205444, +91 9566355386, 99625 88976. Web :www.lemenizinfotech.com/ www.ieeemaster.com Mail : projects@lemenizinfotech.com how the available information can be utilized effectively to reconstruct the full output phase current waveforms in three-phase R- L loads, making it possible to achieve high-performance closed-loop current regulation. Drawbacks: requires the grid harmonic compensation circuits such as the heavy passive series filter to satisfy grid harmonic regulations, which increases cost and size of the system the electrolytic capacitor has high failure rate and lowers the reliability of the overall system Proposed system: The DC-link shunt compensator (DSC), which is connected in DC-link in parallel, is proposed to improve the performances of the single-phase diode rectifier-fed system with small DC-link capacitor. DSC performs the grid current shaping control during the grid connection time, TGC, and boosts the DC-link voltage during the grid disconnection time, TGD. The DC-link boosting control enhances the efficiency of small DC-link capacitor system and overcomes the demerit in the small capacitor system. Lin is a filter inductor to filter the switching ripple current. This can be designed as very small value
- 3. The Master of IEEE Projects Copyright © 2016LeMenizInfotech. All rights reserved LeMenizInfotech 36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue, Pondicherry-605 005. Call: 0413-4205444, +91 9566355386, 99625 88976. Web :www.lemenizinfotech.com/ www.ieeemaster.com Mail : projects@lemenizinfotech.com in comparison with conventional heavy filter inductor for attenuating low order harmonics. The structure of DSC can be implemented to any topologies which can transfer the power between floating capacitor Cdc2 and DC-link capacitor Cdc1, such as boost, buck, and H-bridge converters. Among these types, the boost converter is used as the DSC in this paper. It is because the H-bridge type needs relatively more components and has lower efficiency than the boost or buck type; the H-bridge converter has total four switches and two of them are always conducted. Between the boost type and the buck type, the boost type has much lower Cdc2 and is much easier to control voltage of floating capacitor vdc2 than the buck type. In the small DC-link capacitor system, DC-link voltage vdc1 is tied to grid voltage. Advantages: Improving the system performances Low Total Harmonic Distortion (THD) High efficiency
- 4. The Master of IEEE Projects Copyright © 2016LeMenizInfotech. All rights reserved LeMenizInfotech 36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue, Pondicherry-605 005. Call: 0413-4205444, +91 9566355386, 99625 88976. Web :www.lemenizinfotech.com/ www.ieeemaster.com Mail : projects@lemenizinfotech.com Applications: Home appliances Renewable energy systems Electrical vehicle chargers Block diagram: AC Supply Rectifier DC link shunt compensator (BOOST CIRCUIT) 3-phase inverter Load Driver circuit Isolation circuit Buffer circuit Micro controller circuit 12V dc Supply 12V dc Supply 5V dc Supply