The PQSine S series is an active harmonic filter system designed to eliminate harmonic oscillations and consequently reduce costs. PQSine S series monitors the current signal and compensates the unwanted elements of the measured current. Thus, the filter ensures harmonic suppression independently of the number of loads. It also corrects the power factor, improving the system efficiency while reducing harmonic pollution.
Without PQSine Harmonic disturbances caused by e.g. non-linear loads |
With PQSine Reactive power harmonic oscillations are actively compensated |
PQSine at a glance:
Features
- Harmonic compensation up to 50th harmonic
- Ultra-fast reactive power compensation (inductive and capacitive)
- Load balancing between phases and unloaded neutral wire
- Compact design
- Modular system extendable from 25 A to 600 A
- Grid resonance detection
- Advanced digital control algorithm
- Ethernet and MODBUS inferace
- User-friendly menu operation
- High performance and reliability
- Simple installation
Typical applications
Fast current harmonics and reactive power suppression e.g. for:
- Data centers
- UPS systems
- Green power generation (e.g. photovoltaics and wind turbines)
- Sensitive equipment manufacturing (e.g. silicon wafer production, semiconductor production)
- Industrial production machines
- Electrical welding systems
- Plastic industry machinery (extruders, injection molders)
- Office buildings and shopping centers (3rd and triple harmonic cancellation and neutral conductor unloading)
Safety features
- Highest safety and reliability
- Overload protection
- Internal short-circuit protection
- Overheating protection
- Overvoltage and undervoltage protection
- Inverter bridge protection
- Resonance protection
- Fan fault alarm
Harmonic pollution is a growing problem with the increasing use of power electronics and non-linear loads (such as variable speed drives, UPS, computers, servers, TV sets, etc.).
The presence of harmonics increases the RMS current in power networks. The circulation of harmonic currents through the system impedance creates voltage harmonics which produce voltage distortions and thus deteriorate the quality of the supply voltage. This leads to higher operating and energy costs, production/process downtimes, overheating and malfunction of equipment.
The active harmonic filters and power optimizers of the PQSine series from EPCOS are based on the latest state of the art in power electronics technology. They are installed in parallel to the polluting loads. The active filter analyzes the line current and its associated harmonics and generates a compensation current which neutralizes the harmonic currents and creates an almost sinusoidal waveform (see Figure 1).
Figure 2 shows the total current harmonic distortion without PQSine. Figure 3 shows the result with activated PQSine, namely a cleaner grid.
In addition to eliminating the harmonics, the PQSine active filter and power optimizer also actively balances the loads to all three phases, performs dynamic VAR compensation and even some transient compensation. These features avoid line resonance and ensure high performance and reliability.
Main benefits |
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- Standardized active filter modules
- Three-phase 4-wire (3P4W) version for neutral current correction (ordering code B44055F4*S*) or three-phase 3-wire (3P3W) version (ordering code B44066F3*S*) for correction of phase currents only
- Floating-point 32 bit DSP, FPGA (integrated)
- Switching / control frequency 20-50 kHz
- Reaction time: approx. 20 μs
- Innovative control algorithm
- Compensation up to 50th harmonic order
- Individually selectable degree of harmonic reduction
- Simple electrical connection of power and control wiring
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Technical data and specifications |
Rated voltage | 380 V (228…456 V) | 480 V (384…552 V) | 690 V (480…790 V) |
Mains frequency | 43…62Hz |
Rated filter current | 25, 35, 50, 60, 100, 150 A | 75, 90 A |
Neutral filtering capability | 3 times the rated filter current (in case of 4 wire device) |
Harmonic current compensation range | 2nd to 50th harmonic order, or specified harmonics 0 to 110% |
Rate of harmonic reduction | > 97% *) |
Typical power losses | < 3% (depending of the load) |
Target power factor | Adjustable from -1 to 1 |
Switching frequency | 20 kHz / 35 kHz |
Reaction time | Approx. 20 μs |
Overall response time | < 5 ms |
Harmonic compensation | Available |
Reactive power compensation | Available |
Unbalance compensation | Available |
Display | All systems include a 7" TFT color control / display unit (touch screen) |
Communication ports | RS485 and network port (RJ45) |
Communication protocols | Modbus (RTU), TCP/IP (Ethernet) |
Fault alarm | Available, max. 500 alarm records |
Noise level | < 56 dB (depending on the model) | < 65 dB (depending on the model) |
Protection functions | Overvoltage, undervoltage, short-circuit, inverter bridge inverse, overcompensation |
Ambient conditions | -10 to +40 °C without derating. Solutions for higher ambient temperatures on request |
Relative humidity | 5 to 95%, non-condensation |
Cooling | 75, 151, 300, 405 L/sec (25-35, 50-60, 75-100, 150 A) | 359 L/sec |
Protection class | IP 20 , (opt. IP30, IP31, IP42, IP 54) according to IEC 529 (customizable) |
Panel color | RAL7035 light grey |
Altitude | 1500; 1% up 1500 m. Between 1500 m to 4000 m, according to GB/T3859.2, the power decreases by 1% for every additional 100 m |
Qualifications | CE, IEEE 61000 | CE, ETL (UL 508 and CSA C22.2 # 2014), IEEE 61000 |
Compliance with standards | IEEE 519, ER G5/4 |
*) For typical harmonic order distortions
Advantages of AHF PQSine S series three-level NPC topology
The AHF PQSine S Series range operates on the basis of a three-level Neutral-Point-Clamped (NPC) topology circuit. As can be seen from the diagrams below, the conventional two-level circuit configuration consists of 6 IGBTs (two IGBT power devices in each phase leg and current path). In case of a three-level topology, the circuit configuration consists of 12 IGBTs (four IGBT power devices in each phase leg and current path).
The three-level NPC circuit can produce three voltage levels at the output: the DC bus plus voltage, zero voltage and DC bus negative voltage. The two-level topology can only connect the output to either the plus bus or the negative bus. It also ensures higher quality and better harmonics of the line-to- line output voltage, thus reducing the output filter requirement and the associated costs.
Main advantages of the three-level NPC topology are:
- Lower losses: only half of the voltage has to be switched, thus reducing the switching losses in the transistor. Three-level solutions are characterized by reduced circuit losses and higher efficiency, thus supporting energy-saving concepts.
- Smaller output current ripple: the NPC three-level topology has a lower ripple in the output current and half of the output voltage transient thanks to a higher quality output voltage. This improves performance and reduces the internal filter requirement.
Two-level topology circuit |
Three-level NPC topology circuit |
Current and switched output voltage for a two‑level topology |
Current and switched output voltage for a three‑level NPC topology |