Hannover Messe 2017
Innovative solutions for industrial electronics
- April 24 to 28, 2017
- Monday to Friday: 9:00 to 18:00
- Hannover Exhibition Grounds, Hannover, Germany
- Hall 13, Stand C66
Welcome to the Hannover Fair 2017! We are presenting our comprehensive and innovative portfolio of EPCOS components for industrial electronics. The focus is on EMC solutions and products for power factor correction.
Minimizing leakage currents with LeaXield™
The EPCOS LeaXield™ active filter module is a solution for the minimization of earth leakage currents in power drive systems with frequency converters. Leakage current can cause RCDs (residual current device) to trip. In some applications this means that RCDs with low thresholds such as 30 mA cannot be used, or only with substantial additional expense. The LeaXield active filter module is connected between the RCD (residual current device) and the EMC input filter of the converter in standard three-phase industrial power grids and does not require an additional power supply.
LeaXield detects the common-mode currents on the load-side via a current sensing transformer. An amplifier generates an inverse of the leakage currents and feeds them to the power line via a capacitor network. This produces almost complete cancellation of the leakage currents. LeaXield is now designed for rated currents of up to 150 A for 3-phase grids at frequencies of 50/60 Hz and a rated voltage of 520 V AC. The active filter can be used in systems with leakage currents of up to 1000 mA. Besides minimizing earth leakage currents, LeaXield active filter modules can also improve the EMC performance of power drive systems in the range up to around 500 kHz. The active filter module achieves typical common-mode attenuation values of up to 30 dB at 4 kHz, 40 dB at 10 kHz, and 15 dB at 150 kHz.
The EPCOS LeaXield module can be retrofitted into existing converter-based installations in order to improve their EMC and the RCD compatibility of the power drive system. Moreover, LeaXield circuits can be integrated into EMC filter solutions in order to downsize the expensive current-compensated filter chokes.
PFC capacitors offer higher inrush current
The two series of EPCOS PhaseCap® Energy for power factor correction offer a significantly higher performance. The components are available with gas or resin-filled housings. They are designed for voltages of 230 V AC to 690 V AC and offer a reactive power of between 5 kvar and 33 kvar.
The life expectancy of the B25674* series of gas-impregnated capacitors has been possible to extend by nearly 40 percent from 130,000 to 180,000 hours. The maximum permissible inrush current was also increased by 25 percent to 500 x IR. The capacitors can also be switched significantly more frequently: For example, the maximum number of switching cycles per year has been doubled from 7,500 to 15,000. The maximum permissible operating temperature as per IEC 60831-1 has also now been raised by 5 K to 60 °C.
The B25675* series of resin-filled capacitors features an even longer life expectancy of 200,000 hours and is likewise designed for a maximum operating temperature of 60 °C and a maximum permissible inrush current of 500 x IR.
A further significantly improved feature of both series is their increased energy density in comparison with the existing types: For the 28 kvar / 440 V types, for example, this has been raised by more than 20 percent from 9.7 kvar/l to 11.8 kvar/l. This also results in compact dimensions: The PhaseCap Energy capacitors feature a diameter of between just 75 mm and 125 mm, depending on the type, and a height of between 164 mm and 224 mm.
Active harmonic filters optimize power quality
The EPCOS PQSine™ series of active harmonic filters significantly optimizes power quality. The modular filter systems are designed for 3-phase networks with and without neutral conductors at rated voltages up to 690 V AC at 50/60 Hz. PQSine active harmonic filters are able to analyze and neutralize current harmonics up to the 50th order. The new filter series is available in steps of 60 A (400 V version) or 140 A (690 V version) up to a maximum rated current of 600 A (400 V version) or 560 A (690 V version).
The core of the PQSine active harmonic filter is a controller based on a 32-bit digital signal processor (DSP) that operates at a scanning rate of 48 kHz (400 V version) and 32 kHz (690 V version), respectively. With a reaction time of only 21 µs (400 V) or 32 µs (690 V), respectively, the PQSine active filter is one of the best in its class. The selective drive control (SDC) algorithm is faster than conventional algorithms based on a fast Fourier transform (FFT). In contrast to classical power factor correction, which only corrects inductive loads, PQSine also compensates capacitive reactive power loads. In addition to their outstanding filtering, the PQSine active harmonic filters also balance the loads to all phases. The 4-line versions additionally correct neutral conductor currents.