An Overview on Power Quality Improvement using Multilevel Inverter based Dynamic Voltage Restorer Ms. M. Maheswari 6/21/2014Power Quality Improved using DVR1

Introduction  Quality: A measure of excellence or a state of being free from defects, deficiencies and signifi cant variations.  Power Quality: Worthiness of electrical power to consumer devices i.e. not to disturb or damage appliances and devices. 6/21/2014Power Quality Improved using DVR2

Parameters considered for Power Quality Voltage Magnitude Frequency Wave-shape. 6/21/2014Power Quality Improved using DVR3

Effects of Power Quality  Power Quality issues cause business problems such as: – Lost productivity, wastage of manpower and equipments – Customer and/or management dissatisfaction – Heavy financial impact  According to Electric Light and Power Magazine, 30% to 40 % of All Business Downtime Is Related to Power Quality issues. 6/21/2014Power Quality Improved using DVR4

Why Power Quality is Big issue Presently? – Widespread Usage of Sensitive Loads in all Applications (PLC based equipments, Computers and the like) – For certain devices, a momentary disturbance may result in scrambled data interrupted communications a frozen mouse system crashes and equipment failure 6/21/2014Power Quality Improved using DVR5

Power Quality = Voltage Quality P=V*I * CosΦ V – Supply Voltage – Always Constant I and CosΦ – Depends on the nature of load 6/21/2014Power Quality Improved using DVR6

Power Quality / Voltage Quality Issues Voltage Sag Voltage Swell 6/21/2014Power Quality Improved using DVR7

Power Quality / Voltage Quality Issues 6/21/2014Power Quality Improved using DVR8 Interruption Harmonics

Major Power Quality (PQ) Problems 6/21/2014Power Quality Improved using DVR9 Source: EPRI, 1994 Spikes, 7% Sags, 56% Outages, 6% Swells, 31%

Importance of Voltage Sag 6/21/2014Power Quality Improved using DVR10 Textile Industry Plastics Industry Glass Industry Process Industry Semiconductors Rs.60kRs. 60LRs6 Cr Rs. 60 Cr Losses per Voltage Sag Event Rs.600k

PQ Improvement Techniques  Series Compensation  DVR  SSC  Shunt Compensation  STATCOM  TCSC  Series and Shunt Compensation TCSC  UPFC 6/21/2014Power Quality Improved using DVR11

Dynamic Voltage Restorer (DVR)  Series compensation device  Protects sensitive electric loads from PQ problems  Implemented through power electronic controllers that use voltage source converters (VSC). 6/21/2014Power Quality Improved using DVR12

Block Diagram of DVR 6/21/2014Power Quality Improved using DVR13

Operation of DVR 6/21/2014Power Quality Improved using DVR14

Twentyseven Level Inverter 6/21/2014Power Quality Improved using DVR15

Questions??? 6/21/2014Power Quality Improved using DVR16

6/21/2014Power Quality Improved using DVR17