Automatic
voltage regulators
For precision regulated input ac voltage to your systems
TSi manufactures two ac automatic voltage regulator (AVR) topologies. The first group consists of tap switching transformers, conventionally referred to as AVR. The second group of voltage regulators, the VRp Series, utilizes TSi's new electronic PWM 'no-break' voltage regulation technology, still AVR, but sometimes referred to as PWM AVR or EVR, or pulse-width modulated voltage regulation, which utilizes IGBTs and microcontrollers to modify the sine wave to an optimal wave shape.
Traditional AVR used to be considered the more heavy duty of the two voltage regulation topologies for developing country applications. Over time, the newer electronic pulse width modulation based VRp Series has proven itself as not only the more precise methodology, useable on any kind of load, but also is now preferred for use in countries with quite aberrant power as well as those with relatively stable power, such as the US, Europe, etc.
As there are many different series/configurations possible, please look at the detailed descriptions below, and at the Series features table at the bottom of the page, to help determine the series you need. We also welcome your phone call to discuss your specific application requirements.
Automatic voltage regulator series
VRp
~ VRp stands for voltage regulation with
precision. VRp provides output voltage within plus/minus 3% of nominal, for
input voltage that may vary wildly, e.g. 172 to 276 vac instead of a stable
230 vac. There is no switching of
taps or otherwise a break in the power path thanks to continuous PWM
switching of a buck-boost transformer. The VRp voltage regulator is designed
for applications that require absolutely stable, high-reliability power,
without switching components in the power path. The low-weight, high
efficiency VRp electronic voltage regulator is easy to install in any
environment. The automatic bypass assures that connected equipment will not
shut down, even if the VRp fails. VRp is compatible with all loads as it
does not switch any components in the power path. VRp’s ultra-low impedance
assures stability even with the most demanding loads.
The VRp Series, in 2 to 30 kW output single-phase models, and 6 to 90 kW
output three-phase models, provides cycle-by-cycle voltage regulation by
using 15 KHz microprocessor-controlled IGBT switching technology with 96% or
higher power conversion efficiency. The extremely fast input voltage
detection and correction time of 20 ms (about 50 to 200 times faster than
traditional servo-motor controlled AVR and about 20 to 50 times faster than
relay/triac/scr based tap-changing AVR) ensures protection of even the most
sensitive and mission-critical telecom, medical, instruments and production
equipment. VRp Series units provide a significant portion of a good high
availability power strategy, yet are only a small fraction of the size,
weight and cost of an equally sized UPS system.
Standard
VRp Series
single phase models include:
VRp-2000-120V ~ 120 vac, 2 kVA (please call)
VRp-3000-5000-120V ~ 120 vac, 3 kVA and 5 kVA
VRp-7500-120V ~ 120 vac, 7.5 kVA (please call)
VRp-1000-230V ~ 230 vac, 1 kVA
VRp-2000-0275 ~ 230 vac, 2 kVA
VRp-2100-0228-0233 ~ 230 vac, 2.1 kVA
VRp-3000/5000-02xx ~ 230 vac, 3 kVA and 5 kVA
VRp-3500 ~ 230 vac, 3.5 kVA
VRp-4000-0235 ~ 208 vac, 4 kVA
VRp-7500-10000 ~ 230 vac, 7.5 kVA and 10 kVA
VRp-15000-20000 ~ 230 vac, 15 kVA and 20 kVA
VRp-25000-30000 ~ 230 vac, 25 kVA and 30 kVA (please call)
Other sizes are available up to 90 kVA for OEM,
bespoke/custom applications, please call the factory
for help or to discuss requirements.
Standard VRp Series three phase models include:
VRp-6000-120/208Y ~ 120/208 vac three phase wye, 6 kVA and 9 kVA (please
call)
VRp-9000-16500-120/208Y ~ 120/208 vac three phase wye, 9 kVA and 16.5
kVA
VRp-15000-22500-120/208Y ~ 120/208 vac three phase wye, 15 kVA and 22.5 kVA
(please call)
VRp-45000-120/208Y ~ 120/208 vac three phase wye, 45 kVA (please call)
VRp-6000-0339 ~ 230/400 vac three phase wye, 6 kVA and 9 kVA (please call)
VRp-9000-16500-0339 ~ 230/400 vac three phase wye, 9 kVA and 16.5 kVA
VRp-22500-30000-0339 ~ 230/400 vac three phase wye, 22.5 kVA and 30 kVA
VRp-45000-60000-0339 ~ 230/400 vac three phase wye, 45 kVA and 60 kVA
(please call)
VRp-75000-90000-0339 ~ 230/400 vac three phase wye, 75 kVA and 90 kVA
(please call)
Other sizes are available up to 270 kVA for OEM, bespoke/custom applications.
(Please note: for units with isolation transformer output, please see farther
down on the page. Enclosures will vary with size and application/OEM
requirements)
Dual
range ILc-VRp ~ The ILc-VRp dual range automatic precision voltage
regulator with built-in low-impedance isolation transformer allows
trouble-free operation of electronic equipment over a very wide ac voltage
range of 120 or 240 vac + / - 20 % found in many developing countries. Dual
voltage input enables use with either 120 vac or 240 vac power. Dual voltage
output enables 115 vac via two NEMA 5-15R receptacles, and/or 230 vac via
one BS 1362 socket. Output regulation responds in less than one line cycle
and corrects output voltage to + / - 2.5 % with 20,000 corrections per
second. There is no switching of taps or otherwise a break in the power path
as continuous PWM (pulse-width-modulation) switching of the primary winding
of a buck-boost transformer leaves the secondary power path intact.
ILc-2000-VRp-Dual-Range ~ Input: 120 or 240 vac. Output: 115 and/or 230 vac single phase. 2 kVA. (OEMs or systems integrators requiring special plug/receptacle configurations, please call).
FLc
~ The FLc Series ferroresonant constant voltage regulation transformer based
conditioner is recommended for extreme
environments where absolute reliability is a must. The FLc voltage
stabilizer units can replace a dedicated line and reduce harmonics, while
improving system performance. Applications include industrial control
equipment and telephone systems, generator/UPS combinations and other types
of equipment with high availability and reliability requirements. The FLc
Series of voltage stabilizers offers guaranteed constant output voltage via
a ferroresonant transformer, full isolation with a neutral-to-ground bond,
the best surge protection available, excellent noise filtering, as well as
excellent reliability.
FLc-750-1000-1500 ~ 120 vac ~ 750, 1000 and 1500 VA (230 vac models are available).
SLc
~
Four stage tap-switching voltage regulation. Recommended for office and
other moderate environments where there is a need for basic line voltage
regulation and surge protection. The SLc units offer three-step voltage
regulation (plus one normal stage), good surge protection and noise
filtering, quiet operation at an economical price. Applications for these
voltage regulators include photocopiers, telephone and point-of-sale
systems.
SLc-600/1200/1800 ~
120 vac, 600, 1200 or 1800 VA
SLc-600E/1200E/1800E ~
230 vac, 600, 1200 or 1800 VA
Outdoor VRx
~ The Outdoor VRx Series precision automatic voltage regulator (as in
eXterior grade VRp/VRp-ILc), with
optional built-in low-impedance isolation transformer, allows trouble-free operation
of electronic equipment over a very wide mains ac voltage range of
172 to 276 vac found in many developing countries. Output is 230 vac
+/-3% under a normal input range of 172 to 276 vac. There is no switching of
taps nor any break in the power path thanks to continuous pulse width
modulation (PWM) switching of a buck-boost transformer primary winding.
Units feature an over-voltage cutoff, with automatic restart when ac mains
voltage returns to normal (safe) condition. Also, there is a
failsafe/automatic bypass (even during bypass, the over-voltage protection
is active).
Designed for applications where absolutely safe and precisely regulated ac power is required, such as radio base stations (RBS), telecommunication transmission sites for backhaul (including microwave links), TV/ radio broadcasting, industrial equipment and end-of-line utility equipment.
OutdoorVRx-4400-0455/0460 ~ 230 vac single phase, 4.4 kVA. Other sizes are available up to 15 kVA single phase, and up to 30 kVA dual/three phase.
Outdoor VRp-ILc
~ The Outdoor VRp-ILc Series precision automatic voltage regulator with
built-in low-impedance isolation transformer allows trouble-free operation
of electronic equipment over a very wide mains ac voltage range of
400V+/-20% found in many developing countries.
Output is within 230/400 vac +/-3% under a normal input range of 400 vac +/-20%.
There is no switching of taps nor any break in the power path thanks to continuous pulse width modulation (PWM) switching of a buck-boost transformer primary winding. Units feature an over-voltage cutoff, with automatic restart when ac mains voltage returns to normal (safe) condition. Also, there is a failsafe/automatic bypass (even during bypass, the over-voltage protection is active).
OutdoorVRp-ILc-15000/30000-5339 ~ 400 vac three phase delta
input, 230/400 vac three phase wye output, 15 or 30 kVA. Other sizes are available, please
call.
Designed for applications where absolutely safe and precisely regulated ac
power is required, such as radio base stations (RBS), telecommunication
transmission sites for backhaul (including microwave links), TV/ radio
broadcasting, industrial equipment and "end of line" applications to help
customers experiencing low voltage or intermittent sags and brownouts.
An OutdoorVRp-30000 in rural Sweden. Photo courtesy Mr. Bo Lindemark,
Sweden.
VRp, VRp-ILc (and Outdoor), FLc and SLc features table
| Features | Series | |||
| VRp | VRp-ILc | SLc | FLc | |
| PWM precision voltage regulation +/- 3% | ||||
| Input/output isolation transformer | ||||
| Filtering and surge protection | ||||
| Over/under-voltage cutoff (most models) | ||||
| Wide voltage input window | ||||
| Ferroresonant CVT regulation +/-3% | ||||
| 4 stage tap-switching regulation +/- 10% | ||||
| Automatic bypass | ||||
| Outdoor option (in Outdoor/VRx models) | ||||
TSi Power also manufactures custom/bespoke precision automatic voltage regulators with optional isolation transformer with neutral-ground bonded output. Please call for more information.

