TECHNICAL USER´S MANUAL
3
Thyristor modules
1 – Introduction
1.1 General Description
Thyristor modules are designed to switch capacitive loads up to 80kVAr in power factor
correction (PFC) applications. The modules can switch capacitive loads within 10ms of receiving
a triggering signal. The microprocessor-based architecture and its algorithm senses the voltage
zero crossing, thereby avoiding capacitor abrasion. The modules can switch up to 480V, star- or
delta-connected symmetrical or asymmetrical, resistive, inductive and capacitive loads during
the voltage-zero crossing. Triggering is easily performed through power factor correction relays,
or PLCs. The advantages of the thyristor modules over state-of-the-art mechanical contactors
include: (1) longer life expectancy, (2) fast switching performance, (3) guaranteed minimal
voltage or current transients during switching which (4) extends the capacitor lifetime. Thyristor
modules monitor voltage, status and, temperature. Detected faults are displayed on the four
LEDs on the front panel and recorded in the module internal memory. The modules can operate
with or without a detuned filter reactor. The modules protect detuned filter reactors against
overheating through their external thermostat connections. Thyristor modules are maintenance
free and quiet.
1.2 Application Areas
Thyristor modules are designed for dynamic power factor correction applications requiring
extremely fast and frequent switching actions. Applications include, but are not limited to,
welding, presses, elevators, cranes, arc furnaces, wind turbines and similar areas with
dynamically varying loads.
2 – Technical Specifications
Technical specifications of the 12kVAr, 25kVAr, 50kVAr and 80kVAr thyristor modules are
listed in Table 2.1. This table gives guaranteed ratings and exceeding these guaranteed ratings
will significantly reduce module life expectancy.
Table 2.1:
Technical specifications for 12kVAr, 25kVAr, 50kVAr, and 80kVAr
Parameter
Units
12kVAr
25kVAr
50kVAr
80kVAr
Nominal Voltage
V
400 ±%14
400 ±%14
400 ±%14
400 ±%14
Maximum Blocking Voltage
V
1600
1600
1600
1600
Maximum Operating
Current
A
20
40
80
115
Maximum
di/dt
A/µs
50
100
140
140
Conductor Cross Section
mm
2
16
16
35
35
Number of Semicoductor
Modules
-
2
2
2
2
Auxiliary Supply Voltage
V
-
-
230±%10
230±%10
Fan Power Rating
VA
-
-
32
32
