Servo Voltage Stablizer’s (Linear type)

Trans Power Soluons is manufacturing wide range of LT AUTOMATIC VOLTAGE REGULATORS also commonly called as SERVO STABILIZERS. Voltage fluctuaon is a common phenomenon in every part of the country. Inspite of best e orts, Public uµlity companies can not ensure quality power to consumers due to long and inadequate distribu]on lines and irregular load paerns on distribu]on network. The stable Input supply is a basic necessity of sophiscated equipment to give opmal performance. Major industrial loads are inducve in nature (i.e .A.C. Motors) and they draw considerably high current at high & low voltages resulng in higher losses which in turn increases the temperature of motors thereby reducing the motor life. Further the industrial units running round the clock usually faces problem of low and high voltage due to fluctuang load. Due to this electric motors draw considerably high current at Low & high voltage which e ects the electrical motors. Other equipment’s that are a ected by high & Low voltages are Lighng loads (Bulbs & Tubes) Air condioning plants Elevators & lis, Medical equipment’s etc.

BENEFITS OF AUTOMATIC VOLTAGE REGULATOR

In case, you find that your input voltage is higher even for few hours a day – then you can reduce failure rate of electrical equipment by installing “TPS” AVR & will have following advantages :—

  1. REDUCTION IN BREAKDOWN OF ELECTRICAL EQUIPMENTS:

Maximum load in industries consist of motors, heaters & compressors. At high voltage they draw higher current thus increasing the power Consumpon & MDI and reducing the power factor. Electrical equipment’s are designed for 230 Volts (1-Ph) i.e. 400 Volts (3-Ph) and have maximum e ciency at this voltage. These heavy electrical equipment’s draw considerably more power at

BENEFITS OF SERVO

  1. Reducon in breakdown of electrical Equipments
  2. Energy saving
  3. Reducon in MDI (max. Demand indicator)
  4. Improvement in power factor
  5. Protecon against single phasing
  6. Uniform quality of end product & increase in output
  7. Pay-back period

higher voltage thus increasing the electricity bill of the industry. Similarly in the case of bulbs & tubes the percentages increase of power consumpon will be more than double the percentage increase of voltage. The higher voltage also results into higher losses causing electrical motors to overheat and thereby premature winding failure.

It is therefore advisable to install Servo Voltage Stabilizer which results in 60% – 80% reducon in breakdown of motors, contactor coils, bulbs, tubes etc. depending upon the Input Voltage variaon and working hours of the plant. The table below gives approximate quantave reducon in breakdown of electrical equipment’s by use of Automac Voltage Regulator at various voltage fluctuaon levels.

Input Voltage Possible % reduction In Breakdown Appx. Power saving possible
Range Motor load below 10hp Lighting load Motor load below 10hp Lighting load
380-400 volts Nil Nil Nil No Servo required
400-420 volts 5% 10% 3% 5%
420-440 volts 10% 20% 5% 10%
440-460 volts 40% 40% 7% 20%
460-480 volts 60% 60% 10% 30%

ENERGY SAVING:

As explained previously the electrical equipment’s are generally designed for 230 Volts (1-Ph) i.e. 400 Volts (3-Ph) and have maximum e ciency. Increase or decrease in voltage results in drawing higher current thus increasing the losses of the Motors. These higher losses of electric motors also increase the losses of cables, switches, transformers and other associated equipment’s. With the stabilized voltage at 390-400 Volts, the extra losses generated due to low/high voltage can be considerably reduced resulting in energy saving. With the installation of AVR, 10%-15% power saving is certainly possible.

REDUCTION IN MDI (Max. Demand Indicator):

There will be definite reducon in MDI by 10% – 15% aer the installaon of an AVR.  MDI is a mulµplicaon of voltage & current and is half an hour reading. At higher input voltage, the current  of electric motors also increases. So, the MDI also increases. For Example: Consider a 10H.P.Motor

 

Suppose, current at 400 Volts = 12 Amps
Current at 450 Volts = 14 Amps
MDI at 400 Volts = (400 x 12) / 1000 = 4.8 KVA
MDI at 450 Volts = (450 x 14) / 1000 = 6.3 KVA

% increase in MDI at 450 Volts as compared to 400 Volts = ((6.3 – 4.8)/ 4.8) x 100% =31.25% Even if the high voltage occurs for half an hour in a month, the MDI increases. With the ininstallation of the AVR, the voltage will be controlled and MDI will also be controlled.

 

IMPROVEMENT IN POWER FACTOR:

Whenever the voltage increases above 440 Volts, there is a sharp reducon in power factor at least

 

by square funcon of voltage. At higher input voltage, (i.e. >400 Volts), excitaon current (No Load Current) of the industrial motors increases. The power factor of no load current is normally (0.2). So with the increase in voltage, the excitaon current also increases which further lowers the power factor. By maintaining constant voltage at 390/400 Volts with help of AVR, there will be definite improvement in power factor by 10%-15%.

 

PROTECTION AGAINST SINGLE PHASING :

In the case of single phasing, The line current increases by 1.5 mes which results in higher current flow through the relays, contractors, cables etc. Due to fluctuating voltage, the Electricians sets the overload relay at 15% to 20% higher to avoid frequent tripping of motors in starter panels. Thus the relay will take 4-6 minutes to trip in case of single phasing. However higher seng of overload relays have very little safety margin against single phasing and overloading conditions.

During single Phasing, the line current increase, which may also produce sparks and may sometimes damage the switchgear and may also cause a fire. Further, the higher current overheats the motors within short me resulting in burning/damage of motors. The motor, particularly of smaller capacity motors, say upto 7.5 H.P cannot ithstand this high current for a long me and in most of the cases it burns out before the relay trips.

With the installaon of the stabilizer and maintaining 390/400 volts, the motor will operate smoothly drawing 15%-20% lesser current and correspondingly the relay seng can be reduced by 15%-20% In case single phasing occurs, the relay will trip in 40-50 seconds. The motor can withstand the high current for this period and will be safe. Also, the relays, contactors, sswitchgear etc. incorporated with the motor will be safe

 

UNIFORM QUALITY OF END PRODUCT & INCREASE IN OUTPUT:

With stabilized input voltage to your sensivve producon equipment, you can ensure that your producon processes run consistently & connuously, without any interrupon / aberraon, thus ensuring uniform quality of end product as well as an increase in output.

 

PAY-BACK PERIOD:

Owing to the high e ciency of “TPS” AVR (> 99% in avg. running condions) and its associated benefits, the payback period of “TPS” AVR is normally within 6-12 months, depending upon the input variaon and the number of working hours.

 

BASIC CONCEPT AND DESCRIPTION OF TPS MAKE AVR.

“TPS” Roller contact type Servo stabilizer primarily consists of following major assemblies.

  • LINEAR TYPE VERTICAL ROLLING CONTACT REGULATOR.

In our regulator, we are using heavy section of electrolytic grade rectangular copper strip instead of copper wire to minimize the losses & increase the e ciency of equipment. We are using self lubricating Carbon Roller assemblies instead of ordinary Carbon brushes which o ers more reliability and trouble free performance of the equipment. The coils of Voltage regulator are vacuum impregnated and oven dried as per requirement.

 

  • DOUBLE WOUND BUCK/BOOST TRANSFORMER.

In our Buck/Boost transformer, we are using CRGO laminations to minimize iron losses and coils of Buck/Boost Transformer are wound with heavy secon of m strips electrolyc copper to minimize copper losses for gang beer e ciency of the equipment. The coils of Voltage regulator are vacuum impregnated and oven dried as per requirement.

 

  • DIGITAL CONTROL PANEL WITH DISPLAY UNITS.

We use digital controller for monitoring and controlling voltage. Repair & maintenance of these controllers is very easy.

 

  • AC SYNCHRONOUS MOTOR OF SUITABLE TORQUE.

The Motor is mechanically coupled to the arm of the connuously variable autotransformer which feeds to the primary of a Buck/Boost transformer. The stabilized output voltage is compared with the reference voltage and the resultant error signals control the servo motor providing a true proportional control system rather than On/O  circuit.

 

SUPERIOR FEATURE OF “TPS” MAKE AUTOMATIC VOLTAGE REGULATOR.

 

LOW FLUX DENSITY

TPS Make Automac Voltage Regulators are designed at low Flux density for both Regulator and Buck/ Boost Transformer which reduces No load losses and specially in case of high voltage from system, the Core do not gets saturated and there is no distortion in waveform and adverse e ect.

TEMPERATURE RISE

TPS make Automac Voltage Regulators are designed for max 35˚ C – 40˚ C temperature rise at top of oil at an max ambient temperature of 50˚C. All insulaon used in manufacturing is Class A with thermal index of 105˚C thus giving cushion of 15˚C for condions of overload or sudden jerk load.

LOW CURRENT DENSITY FOR WINDING

TPS Make Automa c Voltage Regulators are designed at low Current density for both Regulator and Buck/ Boost Transformer which increases the rectangular copper strip size to minimize the losses & increase the efficiency of equipment

SIGNAL FOR TRIPPING

As a standard, we are providing signals for tripping in all Automa c Voltage Regulators through our digital controller for the following.

  1. High Voltage cut off / Tripping.
  2. Low Voltage cut off / Tripping
  3. High current cut off / Tripping
  4. Single Phase tripping.

RAW MATERIAL USED IN MANUFACTURING

CORE: The core is constructed from low loss, cold rolled, grain oriented, annealed laminaons of electrical sheet steel conforming to the latest standards using MOH grade laminaons. Further we design our equipment at low flux density which results in low no load losses & higher capacity to bear high voltage of the system.

WINDINGS: Regulator Coils are wounded with TPC paper layer covered copper strip for beer insulaon. The X-secon area of the Electrolyc Grade copper strip used is so designed to give highest quality with minimum losses for the enre running life of the equipment.

RADIATORS: Cooling is provided to keep the temperature as low as possible for higher working e ciency and for all the years with lowest temperature rise even on full load condions.

TANKS & PAINTS: The enclosure/tanks are made of M.S. steel plates / sheets of 3 mm thickness with adequate s eners. All the external and internal surfaces are given a primary coat of Epoxy primer and finishing coat of Epoxy paint for beer life.

OIL: Oil is properly tested for resisvity, dielectric and acidic characterisc conforming to IS 335. Before topping up oil is filtered thoroughly. We use HT grade 11 KV oil even for the LT equipment for beer dielectric strength and high flash point.

Trans Power Solution