InPhase SHAF (Smart Hybrid Active Filter)

InPhase SHAF (Smart Hybrid Active Filter)

The Problem :

There is new challenge created by MSEDCL ( Maharashtra State Electrical Distribution Co. Ltd) to all electrical managers. The challenge is, henceforth PF calculation will be based not only on lagging KVArh but also leading kVARh. What does this exactly mean ??

The distribution companies never consider the average power factor displayed by the energy meter. It calculates PF from kWh & kVArh values. Typically, till now the PF is calculated as :

$$PF = { kWh \over \sqrt{(kWh)^2+ (kVArh   Lag)^2}}$$

From September 2018, MSESDL has decided to calculate PF as

$$PF = { kWh \over \sqrt{(kWh)^2+(kVArh  Lag + kVArh  Lead)^2}}$$

Earlier, nobody looked at the kVArh (Lead) value as it was not considered before. So, it was a normal practice to connect more capacitors than needed (Over compensation). Even an APFC solution, being a stepwise compensation technique & with a sluggish response, toggles between lead & lag kVAr. Now onwards, as the lead kVAr is also going to be accounted for, present APFC system can not ensure a unity PF & so incentives.

So, all HT consumers of MSEDCL who till now enjoyed incentives on energy charges, suddenly faced penalties due to reduced PF.


The solution :

As the capacitor based PF compensation has limitations in the new scenario, there is a need for a different technology which is so fast in responding to the load changes that the compensation is done in milliseconds to ensure unity power factor. Presently Active Harmonic Filter (AHF) is a technology, which complies to the above mentioned requirement & is an ideal solution for the problem.

AHF technology senses the present waveform, injects a compensatory waveform of required magnitude to the electrical system, thereby ensuring unity power factor at all the times.

The difference in the performance can be understood from following diagrams...

Touch Screen

However, higher price is a major deterrent for the use of technology. So, there is a need which calls for a technology which offers similar results as AHF but at a lesser price.

So, InPhase, a leader in Power Quality solutions in India has devised an innovative solution called SHAF (Smart Hybrid Active Filter) which delivers same results of HAF but a lesser price by combining with a existing passive (capacitor based) systems.

The Product :

Cost Effective : Since it uses a combination of Active and Passive it is more cost effective

Less Maintenance : Avoid capacitor, contactor failures due to frequent switching that is prevented by the Active System

Quick Reaction : Since the Active system handles fine correction response and reaction is much faster

High Efficiency : Offers efficiency of 98% over conventional system that has 94 to 95%

Monitor from Mobile : With a 7'inch HMI and ability to manage from cloud it offers more flexibility to monitor and control

Smoother Voltage : Provides smooth voltage profile due to quick reaction time and avoids flicker.

PF & Harmonics : SHAF can manage both PF and Harmonics simultaneously

SHAF Configuration Image

Inexpensive Dynamic Stepless Compensation

  • SHAF at a fraction of the price of a full active solution provides dynamic compensation
  • Realizes stepless and high speed compensation at a lower price point
  • Achieves True PF with options to control harmonics and unbalance
  • SHAF avoids leading compensation there by helping achieving unity PF under KVAH billing
  • Precise Kvar delivery helps to avoid over compensation
  • Over compensation leads to variations in voltage
  • SHAF delivers precise Kvar to ensure Smooth Voltage profile
  • SHAF can do both Leading and Lagging compensation

Works with existing APFC

  • SHAF can work with existing APFC/TSC
  • If APFC/TSC is detuned, then SHAF can work along with it
  • APFC/TSC controller becomes redundant and can be turned off as SHAF will control and monitor the APFC/TSC system.

Buy SHAF get a EMS Free!!!

  • SHAF comes with inbuilt EMS that helps to monitor the whole system at the comfort of your mobile
  • Key information like kWh, KVAr, PF, HDi, are displayed every few minutes in realtime
  • Stores all key data up to 3 months and fault logs for ever
  • Automatically sends SMS during faults

Different Types Power Quality Products Vs Features
Fixed Capacitor Automatic Power Factor Capacitor (APFC) Thyristor Switched Capacitor (TSC)/RTPFC Smart Hybrid Active Filter (SHAF) Active Harmonic Filter - ASTRA
Technology 100% Passive 100% Passive 100% Passive Active & Passive 100% Active
Type of Technology Capacitor with Series Reactor Fixed Contactor switched detuned Capacitor Banks Thristor switched detuned Capacitor Banks combination of detuned capacitor bank along with Smart ASTRA Active Filter
Step compensation / Smooth stepless compensation Step compensation Step compensation Step compensation Smooth stepless compensation Smooth stepless compensation
Harmonics Filtering capability Mostly Not available Mostly Not available Mostly Not available By Active Filter By Active Filter
Unbalance load compensation Mostly Not available Mostly Not available Mostly Not available By Active Filter By Active Filter
Realtime Power parameters monitering - Mobile/computers Mostly Not available Mostly Not available Mostly Not available Available Available
Realtime Panel status monitering - Mobile/computers Mostly Not available Mostly Not available Mostly Not available Available Available
Parallel Resonace risk High High High No No
Individual Harmonics Selection Not possible Not possible Not possible Available Available
Harmonics compensation capacity Not possible Not possible Not possible 2nd to 61st order of Harmonics 3rd to 61st order of Harmonics
Temperature derating capability Not possible Not possible Not possible Available Available
Reaction time slow slow Faster than APFC in mSec Less than 1 mSec
Achieving Fine correction of Power Factor Not possible Not possible Not possible Yes because stepless Yes because stepless
Captive Power Plant (CPP) application No No No Yes Yes
Economical aspects Very less less Moderate Moderate High
Pre-mature Failure indication NO NO NO Yes Yes
Life time because of frequent switching High Very less Moderate High Very less

About Inphase :

Inphase Power Technologies Pvt. Ltd is a Banglore based company, founded by technocrats of more than 100 years of collective experience in power quality, power electronics & software solutions. The team held senior positions in power technology companies before starting the company. Supported by deep understanding of system knowledge & application engineering, Inphase team could create a product which surpasses the global standards. To know more about the company, kindly visit

About Teknocrat's group

Founded in 1993, Teknocrat's Control System (I) Pvt. Ltd. is an experienced Indian industry in the field of Industrial Automation, Energy Conservation & Power quality. Enriched with a long association with global players like Siemens, Schneider, KSB, Emerson, Philips; TCSIPL has a vast domain knowledge about the technologies. It is supported by strong culture of customer focus & process management. Strong installation & after sales suppot team distinguishes TCSIPL from other players in the field. To know more about Teknocrat's group, kindly visit