TDK Electronics · TDK Europe

PQSine® S Presentation

 PQSine Header

The cleaner the grid, the greater the benefit

EPCOS active harmonic filters and power optimizers help to eliminate harmonic pollution from the grid, reduce power quality problems and use energy more efficiently and reliably.


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.

 PQSine Chart 1

Without PQSine – Harmonic disturbances caused by e.g. non-linear loads

 PQSine Chart 2

With PQSine – Reactive power harmonic oscillations are actively compensated

PQSine at a glance:


  • 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 protectionOverheating protection
  • Overvoltage and undervoltage protection
  • Inverter bridge protection
  • Resonance protection
  • Fan fault alarm

Technical data

Main benefits
 PQSine Module

  • 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

Technical data and specifications
Rated voltage380 V
(228...456 V)
480 V
(384...552 V)
690 V
(480...790 V)
Mains frequency43...62 Hz
Rated filter current25, 35, 50, 60, 100, 15075, 90 A
Neutral filtering capability3 times the rated filter current (in case of 4 wire device)
Harmonic current compensation range2nd 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 factorAdjustable from -1 to 1
Switching frequency20 kHz / 35 kHz
Reaction timeApprox. 20 μs
Overall response time< 5 ms
Harmonic compensationAvailable
Reactive power compensationAvailable
Unbalance compensationAvailable
DisplayAll systems include a 7" TFT color control / display unit (touch screen)
Communication portsRS485 and network port (RJ45)
Communication protocolsModbus (RTU), TCP/IP (Ethernet)
Fault alarmAvailable, max. 500 alarm records
Noise level< 56 dB (depending on the model)< 65 dB (depending on the model)
Protection functionsOvervoltage, undervoltage, short-circuit, inverter bridge inverse, overcompensation
Ambient conditions-10 to +40 °C without derating. Solutions for higher ambient temperatures on request
Relative humidity5 to 95%, non-condensation
Cooling75, 151, 300, 405 L/sec
(25-35, 50-60, 75-100, 150 A)
359 L/sec
Protection classIP 20 , (opt. IP30, IP31, IP42, IP 54) according to IEC 529 (customizable)
Panel colorRAL7035 light grey
Altitude1500; 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
QualificationsCE, IEEE 61000CE, ETL (UL 508 and CSA C22.2 # 2014), IEEE 61000
Compliance with standardsIEEE 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.
 PQSine Chart Topology 1

Two-level topology circuit

 PQSine Chart Topology 2

Three-level NPC topology circuit

 PQSine Chart Voltage 1

Current and switched output voltage for a two-level topology

 PQSine Chart Voltage 2

Current and switched output voltage for a three-level NPC topology