### Table of Contents

# Power Quality Analyzer

## Requirements

- 3-phase voltage, current, frequency, measurement
- active, reactive, apparent power, power factor
- neutral current
- harmonics analysis up to 50th order
- quality - swell, dip, interruption, transient/over voltage, inrush current, unbalance rate
- real-time operation
- USB communication interface

## 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

##### Normal grid conditions

##### Phase VL3 disconnected

##### VL2 & VL3 phases disconnected (only VL1 connected)

### 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) |