Use of Smart Meters for Grid discipline through end Consumers

Suggestion for FBB (frequency base billing) for better grid discipline

- Direct Participation of end consumers on grid discipline

SUDHIR KUMAR SRIVASTAV

DGM-RAPDRP

NTPC LIMITED, NEW DELHI

Sudhirksri1@gmail.com

Abstract -This paper gives an insight into the various aspects of FBB (Frequency based billing), its advantage towards grid discipline through self control / regulation by consumers & utilities. The implementation of FBB though complex, but can be achieved through smart meters & shall bring about an immense improvement in grid discipline.

Keywords: FBB (Frequency based billing)

I. INTRODUCTION

Power industry in India is facing a lot of challenges like inadequate capacities in generation, transmission, and distribution, outdated technologies especially in distribution sector, poor maintenance, financial constraints, etc. Due to inadequate generation & high growth in demand, the demand supply gap is widening and peak shortages are worsening day by day.

Major impact of demand & supply gap of electricity, is on the frequency of supply i.e.  change in rotational speed of turbo-generator. Quantum change in rotational speed may lead to out of synchronism of turbo-generator, causing tripping of generator turbine & failure of supply.

As per the Regulatory Commissions Act 1998, the Central Electricity Regulatory Commission (CERC) is authorized to regulate bulk electric power tariffs, viz. the tariff for generation and transmission of power. Similarly State Electricity Regulatory Commission (SERC) is authorized to regulate the tariffs for different category of consumers.

To maintain grid discipline, CERC has introduces ABT mechanism, based on the financial principals, wherein all the Central Sector generators and beneficiaries (i.e., various States) must declare a schedule for generation and drawl for every 15 minutes one day in advance. Any deviation from the schedule is charged at UI rates, which are frequency dependent.

The possible remedies thought in ABT were:

·      Incentivize generators during peak hours.

·      Incentivize generators to back down during off- peak hours.

·      Load curtailment during low frequency & Penalties with objective:

·      Inducing better system operation and grid discipline through commercial incentives and dis-incentives.

·      Capacity charges (fixed cost): Full recovery at normative availability, Apportioned to various beneficiaries as per allocation.

·      Energy charge: Upto scheduled energy, At normative tariff.

·      Unscheduled interchange (UI): Deviation from schedule, UI are frequency linked and are payable/ recoverable depending on grid frequency.

·      Generator generates more than schedule – Gets UI

·      Generator generates less than schedule – Pays UI

·      Beneficiary overdraws power - Pays UI

·      Beneficiary under draws power– Gets UI

Though ABT has brought lot of grid discipline, still this inter-State ABT is a partial solution of the problem because of following:

·      End consumers are not penalised for over drawl during low frequency & there is no participation from end consumers towards grid discipline.

·      Frequent problem of power over drawl from State beneficiaries were observed, leading to the grid instability.

·       Some of the generators are taking advantage of ABT via playing with the loop holes of the rules. (intentional wrong declaration for undue commercial gains)

  

We propose use of FBB (Frequency Based Billing) so that the end consumers can directly participate in grid discipline.

II. SALIENT FEATURES OF FBB    

 We suggest to use SMART METERING facilities for billing the consumers as well as utilities, on the basis of frequency of supply.

If the frequency of supply is low i.e. less than   50 Hz, the consumers / utilities shall be discouraged for drawl of power by overcharging the consumption with multiplying the billed amount with (50/f) ^ 40 for consumers & with (50/f) ^ 60 for utilities.

Here denominator f is less than 50, so multiplying factor is more than 1 & consumer/utility will be overcharged.

Detail calculation at different frequency during under frequency is as below:

Similarly consumers and utilities can be incentivised during high frequency

If frequency of supply is high i.e. when frequency is more than 50 Hz, the consumers / utilities shall be encouraged to draw more power by undercharging the consumption with multiplying the billed amount with (50/f)^40 for consumers & with (50/f)^60 for utilities.

Here denominator f is more than  50, so multiplying factor is less than 1 & consumer / utility will be under charged.

 Detail calculation at different frequency during over frequency is as below.

SMART METERS shall clearly display:

1.    Frequency

2.    Multiplying factor of overcharging / undercharging.

3.    Per unit billing at current frequency.

The display may also give the information of tentative hourly / daily / monthly billing with present load & frequency conditions.

 The meter shall give alerts for high frequency & low frequency at defined / specified values.

 Meter may have facilities to auto cut the high but non-critical loads (as defined by users) when frequency is low.

This auto cut can also be graded with different level of frequency & can be associated with frequency alerts.