Libratherm offers Thyristor Switch Module, specially designed for Real time Power Factor Correction (RTPFC) applications. RTPFC is designed to compensate the reactive power on real time basis for extremely rapid acquisition of the power factor within the range of 100 – 120 millisecond. Connection and disconnection of the capacitor to and from the network occurs at zero crossing.
In RTPFC the capacitor banks of suitably rated KVAR are randomly / sequentially selected, based on the command from the Real time power factor relay module in order to maintain close to unity power factor (Ratio of KW:KVA) or COS Factor. In conventional APFC method, the number of capacitor banks are selected by switching the contactors connected in series with each capacitor bank – Contactor based switching gives delayed correction and hence difficult to maintain PF close to unity.
This LTSM module allows the selection of such capacitor banks using thyristors (i.e. Solid state switch). Thyristors being solid state switch, offers many advantages compared to electromechanical contactors.
Libratherm make LTSM modules are available to switch single or 3 phase capacitor banks rated for 5, 10, 15, 25, 50 and 100 KVAR. Zero cross over switching technique is used to rapidly turn on and turn off the thyristors connected in series with these capacitor banks. LTSM accepts direct potential free contact command and requires Auxiliary DC supply of 12V or 24V @ 1Amp per LTSM.
Advantages of Thyristor switch module over conventional Electromechanical Contactor:
These switching modules LTSM are easy to install and come with built-in indications for normal function and faults, along with built-in protection circuits for fail-safe operations.
Generally, each of the real-time power factor correction (RPFC – relay module) gives 4 to 12 relay outputs, to select that many capacitor banks to maintain the desired power factor and hence it will be required to use that many numbers of LTSM modules of required KVAR ratings.
|Item||Thyristor switch module for capacitor switching.|
|Control Command||12 to 24DC pulse (internally optically isolated) or potential-free contact from external APFC relay module.|
|Firing technique||Guaranteed Zero cross over firing.|
|Load Configuration||2 leg control – SCR module in series with 2 phase and one phase will be direct to Capacitor bank.
(Capacitor bank in 3 wire close delta configuration).
|Switching Devices||2 x SCR/SCR module or SCR/Diode Module of suitable current ratings
to match KVAR of connected capacitor banks (PIV of 2200V / 1800V from Naina Semiconductor/Semikron).
|Switching time||Min. 100mS (5 AC cycles @ 50Hz line frequency).|
|Re-switching time||Depending on the de-tuning factor and discharge resistor across capacitors.|
|Over Temperature Protection||In case of a rise in temperature of the module due to lack of external or forced cooling -
SCR firing will be tripped and will cease to fire, till the temperature is lower than
the preset temperature value of the built-in Thermistor.
|Auxiliary Supply Voltage||12 or 24VDC @ 15WATT max. per LTSM.
We provide suitable 12/24VDC SMPS at an extra cost
based on the number of LTSM to be installed on a single panel.
|LED Indications||For Power ON, THY1 ON, THY2 ON, FAN ON, CB ON, Over Temperature.|
|Three Phase Line Voltage||110 to 500VAC (Special modules are available for 690/750VAC line supply).|
|Mounting||LTSM can be mounted inside the panel on the base plate using 4 screws.|
|LTSM sizes||As per the Ordering Information table.|
|Sr. No.||Model||Product Description||Cooling||Size (H x W x d) mm.||Part No.|
|1||LTSM-5||Thyristor switch module for 5 KVAR capacitor bank||NATURAL||250 x 160 x 130||2910|
|2||LTSM-10||Thyristor switch module for 10 KVAR capacitor bank||NATURAL||250 x 160 x 130||2911|
|3||LTSM-15||Thyristor switch module for 15 KVAR capacitor bank||NATURAL||250 x 160 x 130||2912|
|4||LTSM-25||Thyristor switch module for 25 KVAR capacitor bank||NATURAL||250 x 160 x 180||2913|
|5||LTSM-50||Thyristor switch module for 50 KVAR capacitor bank||FORCED||250 x 160 x 180||2914|
|6||LTSM-75||Thyristor switch module for 75 KVAR capacitor bank||FORCED||250 x 160 x 180||2915|
|7||LTSM-100||Thyristor switch module for 100 KVAR capacitor bank||FORCED||425 x 285 x 280||2916|