Active Harmonic Filter (AHF)
The LSTAY(L) series Active Harmonic Filter is designed for low-voltage power systems to mitigate harmonics, improve power quality, and provide dynamic reactive power compensation. It detects harmonic currents generated by nonlinear loads in real time and outputs reverse compensating current through an IGBT inverter, so that the grid current remains close to a pure sine wave. This helps reduce harmonic distortion, suppress resonance, improve power factor, and protect both the grid and electrical equipment.
Main Features
- Dynamic active filtering for comprehensive power quality improvement.
- DSP-based intelligent control with real-time monitoring.
- Selectable modes for harmonic compensation, reactive power compensation, or combined compensation.
- Supports local, partial, or total compensation, with CT installation on either the power side or load side.
- Capable of compensating phase imbalance.
- High reliability and high efficiency, with full-load loss less than 2.5%.
- Modular design with parallel expansion capability.
- Comprehensive protection functions, including overcurrent, overheat, grid over/under voltage, phase loss, DC bus over/under voltage, and overload current limiting.
- Supports parallel operation of up to 16 units with intelligent redundancy.
Applications
Widely used in rectifiers, converters, chargers, welding equipment, UPS systems, and other nonlinear load applications requiring harmonic mitigation and power quality improvement.
Technical Data
- Rated Compensation Current: 25–200A
- Maximum Parallel Capacity: 800A
- Operating Voltage: 220VAC/400VAC/480VAC/690VAC, -10% to +10%
- Operating Frequency: 45–63Hz
- Harmonic Compensation Rate: >99%
- Filtering Capability: THDi <5%
- Filtering Range: 2nd to 50th harmonics
- Fast Response Time: <300 μs
- Full Response Time: <3ms
- IGBT Switching Frequency: 20kHz
- Communication Interfaces: RS485, RS232, Ethernet, USB2.0, GPRS
- Communication Protocol: Modbus
- Protection Level: IP20, customizable to higher protection levels
- Operating Temperature: -40°C to +50°C
- Cooling Method: Intelligent air cooling
Selection Table
No. | Product Type | Product Name | Module Chassis Dimensions (W x D x H) | Maximum Module Overall Dimensions, Including Mounting Ears |
1 | SVG | LSTSVG-035/400 | 450x580x88 | 520x648x88 |
2 | LSTSVG-050/400 | 450x580x110 | 520x648x110 | |
3 | LSTSVG-075/400 | 450x580x160 | 520x639x160 | |
4 | LSTSVG-100/400 | 450x580x192 | 520x639x192 | |
5 | LSTSVG-150/400 | 680x580x192 | 750x639x192 | |
6 | LSTSVG-120/690 | 680x580x200 | 750x639x200 | |
7 | APF | LSTAY-030/400 | 450x580x88 | 520x648x88 |
8 | LSTAY-050/400 | 450x580x88 | 520x648x88 | |
9 | LSTAY-075/400 | 450x580x110 | 520x648x110 | |
10 | LSTAY-100/400 | 450x580x160 | 520x639x160 | |
11 | LSTAY-150/400 | 450x580x192 | 520x639x192 | |
12 | LSTAY-200/400 | 680x580x192 | 750x639x192 | |
13 | LSTAY-100/690 | 680x580x200 | 750x639x200 |