Thyristor switches for capacitors MTK-2, MTK-3

 Features of switching capacitors UKRM by thyristor switches - Part 2

 

 Contactless thyristor contactors of series MTK-2 and MTK-3 of production JSC Meander (Russia, St. Petersburg) are designed for switching of compensation capacitors in installations for reactive power compensation (UKRM). This reactive power control method is applied to power grids, where the nature of the load changes very quickly, for example, with welding machines, stamping presses, lifts, cranes, controlled electric drive, etc.

 

 The advantage of MTK thyristor modules in comparasion with classical electromagnetic contactors is a connection of  the capacitor to the net without prior discharge. This capability is determined by the algoritm of MTK operation, that is included in the time of equal voltages on conclusions of the capacitor and in the net ("AT ZERO OF CURRENT"). Because of this function follows another important advantage - a significant reduction of transient current pulses. The current pulses cause interferences, that can disrupt the proper operation of the electronic devices, causing considerable damages and even remove them from the system. Furthermore, the service life of capacitors, as therethrough through them flows only rated current. To protect thyristor keys from the peak current in chain should be included an inductance at least 15uH.

 

 Thuristor contactors of series MTK-25 and MTK-26 are thyristor modules, mouted on a common coller, and a control circuit , mounted in one case. In models of MTK-26 is added built-in high-speed fuses. At the front panel of the regulator there is a green LED of indication a state of switch and a red LED of dangerous on capacitor battery.

 

A parameter	Unit	MTK-25-50	MTK-26-50	MTK-25-100	MTK-26-100	MTK-25-150	MTK-26-150
Maximum operating voltage of net	V	480
The maximum allowable voltage	V	1600
Character of the load		C/R/L
Maximum allowable speed of current rise dI/dt	A/mcs	50
The maximum operating current (IRMS) (at a maximum temperature of an environment 450C)	A	50		100		150
A fuse		no	there is	no	there is	no	there is
I²t; Tvj=125°C; 8.3...10ms	A²s	9100	9100	28800	28800	28800	28800
Power *	kVA/V	33/380 35/400 38/440 41/480	33/380 35/400 38/440 41/480	66/380 70/400 76/440 83/480	66/380 70/400 76/440 83/480	99/380 103/400 114/440 125/480	99/380 103/400 114/440 125/480
Maximum power loss	Wt	128	141	256	284	385	427
Rapid discharge of capacitors	30	Built-in module of discharge capacitor
Temperature of activating ventilator	0С	-	-	60±5	60±5	60±5	60±5
Temperature of switch's turning off	0C	100±5
Voltage of control signal	V	DC24±20%
Operating temperature range (different versions)	0C	-25…+55
Storage temperature	0C	-40…+70
Climatic modification and placement category by GOST 15150-69 (non-condensing)		UHL4
The degree's protection according to by GOST 14254-96		IP00
The degree of pollution in accordance with GOST 9920-89		2
Relative humidity of air	%	up to 80 (at 250C)
Heigh above sea level	m	till 2000
Operating position in space		vertical
Mode		round the clock
Cooling		unconstrained		ventilator

* - information for order.

 

Warning!
- Thyristor switches are not designed for the separation of electric circuits, so when connecting the need to take measures to isolate them from the mains.

- The manufacturer constantly improves the design and manufacturing technology, and MTK reserves the right to make changes without lowering product performance.