APF Structure
Sri Neevi PQC Series APF has a modular design. Usually, the SRIN active power filter system consists of one or several APF modules and an optional Liquid Crystal Monitor & Control Panel (LCM). Each APF module is an independent harmonic filtering system, and users can change the harmonic filtering system rating by adding or removing APF modules.
According to the mounting type, the Sri Neevi PQC series APF can be divided into Modular APF and Wall-mounted APF.
Modular APF
APF modules and an LCM panel can be embedded in Delta’s standard APF cabinet or a customised cabinet. There are breakers, cable terminals and a Surge Protection Device (SPD) in the APF cabinet.
A Modular Active Power Filter (APF) consists of independent APF modules combined with a Local Control Module (LCM) panel. These modules can be installed in Delta’s standard APF cabinet or in a fully customised cabinet, depending on the site requirements.
According to cable terminal type, a modular APF can be divided into two types

Wall-mounted APF
Sri Neevi Wall-Mounted Active Power Filter (APF) is designed for low-capacity harmonic mitigation and reactive power compensation in compact spaces. The unit can be securely mounted on a wall, making it ideal for commercial buildings, small industrial loads, and retrofit applications where floor space is limited.
An optional LCM (Local Control Module) can also be integrated with the wall-mounted APF to provide enhanced monitoring, control, and communication features, which are customizable according to customer requirements.

| Parameter | Details |
|---|---|
| Input Voltage Range |
AC 400V: AC 308V ~ 480V AC 690V: AC 432V ~ 880V |
| Electric Connection |
AC 400V: 3P3W / 3P4W AC 690V: 3P3W |
| Rated Current per Module |
AC 400V: 50A, 75A, 100A AC 690V: 100A |
| Redundancy | Each module is an independent filtering system |
| Rated Current per Cabinet |
AC 400V: 50–525A (module combination) AC 690V: 100–500A (module combination) |
| Harmonic Elimination Range |
AC 400V: 2nd–50th order (Selectable) AC 690V: 2nd–31st order (Selectable) |
| Harmonic Filtering Degree | 0–100% programmable per harmonic (Ampere value) |
| Harmonic Filtering Performance | Up to 98% filtering at rated load, THDv < 3%, THDi < 5% |
| Reactive Power Compensation | Supports inductive & capacitive reactive power |
| Reactive Compensation Performance | PF ≥ 0.99 (if APF capacity is sufficient) |
| Response Time |
Full: < 20ms Instant: < 100µs |
| Thermal Loss | ≤ 3% of APF rated capacity (kVA) |
| Output Current Limitation | Automatic (100% rated capacity) |
| Imbalance Correction |
AC 400V: Negative & zero sequence AC 690V: Negative sequence |
| Parallel Expansion (System) |
AC 400V: Up to 10 racks (7 modules/cabinet) AC 690V: Up to 10 racks (5 modules/cabinet) |
| MTBF | > 100,000 hours |
| Parameter | Details |
|---|---|
| Switching Frequency |
AC 400V – 50A, 75A: 60kHz AC 400V – 100A: 30kHz AC 690V: 20kHz |
| Controller | DSP Control |
| Communication | Modbus Protocol, RS232/485 |
| Monitoring | PQC Monitor Software (Optional) |
| Parameter | Details |
|---|---|
| IP Grade | IP20, IP30 or customization |
| Cooling Method | Intelligent forced air cooling |
| Noise Level |
AC 400V: < 65dB(A) @1m AC 690V: < 70dB(A) @1m |
| Dust Filter | Optional |
| Dimension | Refer to APF model table |
| Weight | Refer to APF model table |
| Parameter | Details |
|---|---|
| Ambient Temperature | -10°C ~ 50°C |
| Relative Humidity | 0 ~ 95% |
| Altitude |
≤ 1000m: Rated Capacity 1000–2000m: Derating 1% per 100m |
| Response Time |
Full: < 20ms Instant: < 100µs |
| Thermal Loss | ≤ 3% of APF rated capacity (kVA) |
| Output Current Limitation | Automatic (100% rated capacity) |
| Notes | All specifications are subject to change without notice. |
