Active Power Filter(APF)

Active power filter is used to suppress dynamic harmonic and compensate reactive power. It can compensate the various harmonic and reactive power which can overcome the disadvantages of LC filter such as harmonic suppression and reactive power compensation.



Recently, the number of arc furnace, electrified railway, rectifier, computer and printer, etc equipments in distribution network increases. The non-linearity, impact and unbalanced features contaminate the power quality. In other hand, the modern industry, commercial and residential users are sensitive to the power quality and require highly in it.



The traditional active power filter has low cost, simple structure and convenient maintenance, etc features to be applied widely. It is the main method to suppress system harmonic and compensate reactive power. But the large dimension and filter effect are related with the running situation. In certain situation, the active power filter vibrates with the system. As a result, the past active power filter management technology can't meet the requirements.



Equipment functions:

Provide comprehensive power quality solution.

Reduce harmonic distortion rate

Reduce peak value current

Improve power factor

Reduce line loss

Avoid central line overheat

Avoid data interference and loss

Avoid error operation of circuit-breaker

Avoid damage of capacitance overload

Ensure power system safety.

It provides a comprehensive solution for the equipments in the power grid and filter more than 20 kinds of harmonics.

Eliminate central point zero sequence harmonic current

97% of harmonic filter rate

Control the harmonic

Comply with GB/T14549 and IEEE Std. 519-1992

Control power factor

Balance load current to reduce negative sequence

Set the priority class

Realize single phase filter

Filter the 50th harmonic

Real-time record the fault and incident

Maxmum690V voltage

Parallel connection with present distribution system

Save maintenance cost

Modular design for expansion

Automatically track and compensate the harmonic

Closed loop control to ensure better filter accuracy

Filter feature will not vibrate with system impedance

Response time is less than 100us

Compensation time is less than 5ms.

Support several communication protocols

Apply fiber-electricity isolation

Item

Pre-SAPF3 value

Post-SAPF3 value

Phase A voltage U (V)

211.7

214.3

Phase B voltage U (V)

212.6

215.2

Phase C voltage U (V)

212.5

215.1

THD of phase A voltage (%)

7.15

1.89

THD of phase B voltage (%)

7.21

1.92

THD of phase C voltage (%)

7.25

1.95

Phase A current (A)

476.1

402.3

Phase B current (A)

479.7

409.5

Phase C current (A)

487.8

410.4

THD of phase A current (%)

28.6

2.9

THD of phase B current (%)

28.7

3.2

THD of phase C current (%)

28.8

3.6

Active power P (kW)

254.7

259.2

Reactive Q (kvar)

162.9

34.9

Apparent power (kVA)

306.0

261.6

Power factor

0.83

0.99

SAPF3 consists of controller, IGBT convertor and CT, etc. It filters the harmonics of phase A, B and C and is suitable in the fields without central line or with small harmonic.