Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Radio transmitter design wikipedia , lookup
Operational amplifier wikipedia , lookup
Valve RF amplifier wikipedia , lookup
Crossbar switch wikipedia , lookup
Power MOSFET wikipedia , lookup
Surge protector wikipedia , lookup
Opto-isolator wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Current mirror wikipedia , lookup
Power electronics wikipedia , lookup
DYNAMIC Power Factor Correction EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 1 Target Applications: Welding / spot welding equipment Presses (e.g. most car factories in Germany use meanwhile dynamic PFC) Wind turbines Container cranes Lifts Central motor start up compensation Any fast fluctuating load requires DYNAMIC PFC EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 2 What is DYNAMIC PFC? The usage of new technologies in modern industry claims for faster and more dynamic power factor correction banks that follow the faster process and allow a “real time” power factor correction. The solution is the so called “Dynamic Power Factor Correction”. Dynamic PFC systems use electronic switches rather than contactors – thyristor modules – which allow an infinite number of switching operations on one hand and ensures an extremely fast reaction time upon load changes. High inrush currents one of the big problems while switching shunt capacitors with conventional contactors are eliminated with Thyristor switches due to ZERO CROSSING SWITCHING, means the capacitor is connected during ZERO crossing of the sinusoidal wave and therefore no inrush currents are caused. EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 3 Customer benefits of DYNAMIC PFC 1. Elimination of reactive power drawn from power utilities, reduction of electricity cost also with fast fluctuating loads; duty cycles of a few seconds are possible 2. Fast switching without delay time for discharging (< 20 ms) 3. Cost saving: investment reduction for new equipment (distribution equipment, transformer, cable cross section etc.), due to cutting-off of peak loads 4. Stabilizing of grid voltage, means avoiding of voltage drop, e.g. welding therefore improvement of welding process in terms of quality but also in time 5. Avoiding of flickering 6. Smooth switching, transients power quality will be improved 7. Increase of life time of a capacitor bank due to contact less switching and smooth switching (switching device as well as capacitors) EPCOS AG FK PM PFC (RM) free (voltage DYNAMIC PFC as well as 30.04.2003 current), Page: 4 N E T Z L A S T EchtzeitBlindleistungsregler TSM – C 1 ... n Real time Power factor controller DynamiC Reaction-time: about 20 ms EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 5 Features expected of dynamic PFC? Transient-free switching Power factor correction with high switching frequency Minimal reaction-time Free of wear out Enhancement of power quality Flicker-compensation EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 6 TSM-C Thyristor switch TSM – C for Active (dynamic, real time) PFC Fast Thyristor switch for capacitive loads up to 50 kvar. The TSM-C is a fast electronically controlled, selfobserving thyristor switch for capacitive loads up to 50 kvar, which is capable to switch PFC capacitors within a few milliseconds as often as required. EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 7 TSM-C Thyristor switch The TSM-C observes permanently: - voltage (availability & value) - phase sequence - capacitor rated current - temperature of the power switches When voltage problems occur, the TSM turns-off. By supervising of the capacitor-current it is possible to identify dangerous operating conditions, such as harmonic distortion. High current harmonics may cause the destruction of the connected PFC capacitor. Over currents are measured by an integrated measuring system. The module turns-off as long as the overload exists. The highly advanced measuring circuit for self-observing of the thyristor switch protects the capacitor and the application as well. The alarm-signal of the temperature trigger switches-off the corresponding capacitor branch. After dis-connection the thyristor switch will cool down again, if the temperature decreases below the preset threshold value, the module will reconnect. EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 8 TSM-C Features: 1. Easy installation: it can be used identically as a contactor and can be put into operation even with a standard controller (our recommendation is the BR6000-T controller with transistor output). All the intelligence needed is offered with the thyristor module itself. 2. The TSM-C is a fast electronically controlled, self-observing power switch for capacitive loads up to 50 kvar 3. Due to “full wave switching” no harmonics generated by TSM-C 4. Very fast reaction time: < 7 milliseconds only 5. Permanent self-controlling of: - voltage parameter - capacitor-current - temperature of the thyristor-switch. 6. Cascading output 7. Alarm output per module 8. Compact and modern design EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 9 TSM-C high end design : 1. Modern design with compact casing 2. 2 high voltage thyristor modules 3. 2 large heat sinks 4. 2 current transformer 5. Intelligent control board for zero crossing switching 6. Firing board for thyristor firing 7. PCB for self diagnostic of all important electrical and thermal parameters 8. Front plate with operation and error message display EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 10 Comparison of inrush current Left hand graph shows a inrush current of 157 times nominal current caused by PFC capacitor parallel switching with standard motor contactor. EPCOS AG FK PM PFC (RM) The thyristor connects the capacitor with almost Zero delay time. As soon as the control signal is applied to the thyristor, it starts carrying the capacitor current, means ULTRA FAST switching. At the same time this graph shows that the current is starting from ZERO (Xaxis), up to its maximum value without any inrush current effect. >> no inrush current << DYNAMIC PFC 30.04.2003 Page: 11 Switching at ZERO crossing EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 12 Reduction of apparent power saves investments EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 13 TOWER AUTOMOTIVE – PRESS AND WELDING CENTER EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 14 Real case in Germany, a supplier for Volkswagen (pressing of sheet steel) • Huge presses for forming the metal sheet steels, up to 7500 tones • Huge load fluctuation • Due to further adding of a new press of 7500 tons the electrical system was over loaded • The factory owner was very much convinced that this system pays off very fast even if it is much more expensive than a conventional capacitor bank. But this can not be compared anyhow! • Reasons for him: Fast compensation and eliminating reactive power drawn from energy supplier Improvement of power quality (e.g. flickering) 2500 Ampere bus bar still OK, means a new investment for a new 3500 A bus system through the factory and a new supply transformer (+ building) can be avoided • The factory owner was very much convinced and ensured me that he will definitely go for Real Time PFC with the next extensions of the factory. EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 15 Conventional and dynamic PFC, mixed operation (hybrid mode) Usually for power factor controllers, only conventional PFC via contactors or dynamical compensation via thyristor switches is possible. A unique feature of BR6000 is the so called „mixed operation“, means the basic load is compensated with contactors, but only the fast changing load peaks are compensated via thyristors. Therefore, not the complete system needs to be equipped with the very costly thyristors, but only a few stages! EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 16 Conventional (relay output) and dynamic PFC (transistor output) EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 17 Conventional (relay output) and dynamic PFC (transistor output) EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 18 Attention: Don’t touch live parts in the PFC equip., even disconnected caps are loaded up to 1500 VDC!! Warning signs in the equipment required!! Wait 10 minutes after the main switch is turned off – until the voltage in the system is down to an uncritical value. In non-detuned systems (400V grid) you need capacitors with a voltage of 440 V ! In de-tuned systems (400 V grid) you need capacitors with a voltage of 525 V ! For discharging the capacitors special high-voltage resistors type EW22 are required. Standard resistors can not be used! In dynamical PFC systems discharge reactors cannot be used! (this would cause a shortcut of the high-voltage DC ) In PFC systems without filter circuit reactors current limiting reactors are required ( e.g. BD-100 ) for the TSM. EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 19 Example of RT PFC module: to compact, to hot!!! EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 20 Example of REAL TIME PFC panel EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 21 Accessories for REAL TIME PFC 1. Discharge resistors: EW-22 - Discharge resistors for PFC capacitor - For usage with TSM-C thyristor module (Discharge reactors are not allowed!) Power: Voltage: 100 W 1200 V 2. Inrush current limiting coil: BD 100 - Current limiting coil for reduction of inrush currents - For usage with TSM-C thyristor module - Max. current 100 A 3. Over current protection: NH-SF-80 / NH-SF-160 - Electronic super-fast fuses - For protection of the thyristor module and PFC modules EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 22 Dynamic PFC Module: TSM-AT Features: Real 3-phase-switching (single phase capacitors) Output up to 100 kvar at 690 V Usage for PFC-systems with and without reactors Connected load (output) programmable Easy programming for the individual application Via multi-lingual plain language display Indication of all relevant parameters of the grid Alarm output and error message storage EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 23 Dynamic PFC Module: TSM-AT EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 24 Dynamic PFC Module: TSM-AT EPCOS AG FK PM PFC (RM) DYNAMIC PFC 30.04.2003 Page: 25