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Impact of demand-side management system Chapter | 15 391

So the small size of PV plant and ES is required with the DSM scheme. In
other words, it reduces the capital cost of the system.

15.2 Analysis of AC microgrid and DC microgrid
The converter stage, energy demand, and size of power sources (battery and
PV plant) are considered in this study for comparative analysis of the AC
microgrid and DC microgrid.

15.2.1 Converter stages
The DC loads are increasing in the residential as well as commercial build-
ing due to the high efficiency of the DC load as compared to the AC com-
patible load. It forced to interconnect the AC DC converters in the case of
the traditional distribution system (AC system) to supply the DC loads
[11,12]. These conversion stages at the load end are one of the causes to
decrease the system efficiency and increase the system cost. The details of
the conversion stages with AC system in an autonomous DC microgrid for
residential building can be found in Table 15.1.

TABLE 15.1 Source and appliances internal converters and their efficiency
and cost.

Source Traditional AC system
Power Type of Efficiency Number Price Total cost
converters (%) [13] (Rupees) (Rupees)
PV plant DC DC AC 89 1 7000 7000
Battery DC AC DC AC 83 1 7000 7000
Loads
LED bulbs DC AC DC 84 5 50 250
Tube lights DC AC DC 84 5 50 250
Fans DC AC DC 85 3 150 450
Pump DC AC DC 85 1 450 450
Washing DC AC DC 85 1 450 450
machine
Refrigerator DC AC DC 85 1 450 450
Total converters cost (Rupees) 16,300
AC, Alternating current; DC, Direct current; LED, Light Emitting Diode