Table of Contents

Power Quality Analyzer

Requirements

AC sensors

AC voltage sensors

For three-phase balanced system, the sum of instantaneous values of phase voltages (as well as currents) is zero: $$v_{L1} + v_{L2} + v_{L3} = i_{L1} + i_{L2} + i_{L3} = 0$$ In such case also $$u_{N1} = u_{N2} = 0$$ and $$v_1 = v_{L1}\frac{R_{12}}{R_{11} + R_{12}}$$

SPICE simulation

Voltage divider for measuring phase voltages - SPICE simulation schema

 SPICE simulation of AC voltage divider

Normal grid conditions

 SPICE simulation - grid ok

Phase VL3 disconnected

 SPICE simulation - VL3 phase disconnected

VL2 & VL3 phases disconnected (only VL1 connected)

 SPICE simulation - VL2 & VL3 phases disconnected

Power supply

Component Max. consumption [mA] # Total consumption [mA]
ACS712 13 4 52
TL064 (TL084) 1 (12) 2 2 (24)
78xx/79xx 6 3 18
Total 72 (94)

Schema

AC sensors

AC sensors