Nine Minutes Blackout Call

To keep the involvement of the people alive in the lockdown Honourable Prime Minister Shri Narendra Modi announced that on 5th April 2020 Sunday at 09:00 PM we have to shut down all electrical lamps for 09 minutes to show out the unity of the country to fight Corona Virus (COVID-19). And we will do this as a united nation INDIA.

The demand is expected to reduce by about 15 GW during the nine minutes. But there are some effects of a sudden sharp fall and rise because already Industries, Railways and some Commercial loads are shut down and mostly Residential loads (Lamps, TV, AC, other home appliances, etc.) are alive, due to that power generation is reduced drastically and generation is going on at 30-35% of capacity.

The power generation in India principally by Thermal power station and Hydropower station. In that operating and controlling of the hydropower station (HPS) is easy as compared to the thermal power station (TPS) i.e. HPS are easy to start and shutdown by regulating the flow of water than TPS (in which coal is burnt first produce heat to raise steam and steam drives a turbine to drive an alternator which finally generates electricity). 

Now at this time, major loads on the grids (In India there are five regional grids: Northern, Eastern, Western, North Eastern, and Southern Grids.) are lights, TVs, ACs, Agricultural pumps, etc. As the generation is principally by TPS and most of HPS are not operating due to light load on the power grid.

When the whole country will shut down lamps on 5th April 2020 there will be a sudden reduction in load on the grid but at this time generation (which is principally due to TPS) cannot be stopped (or cannot be controlled easily due to its kind of operation) and therefore generation is more and load is suddenly reduced; this is a kind of open circuit fault because at 09:00PM power generation will be there and at the consumer side, no one will be using power.

This may lead to transient stability issues and the grid can collapse.

So can we stop the generation?

No, we cannot plan generation to shut down because TPS will take much time to shut down generation (Coal Burning-Steam-Turbine rotation-Alternator-Electricity) and resynchronization problem after 09:09 PM (i.e. after 09 Minutes).

What you can do?

To avoid this sudden fall and rise due to 09 minutes of shutdown you can continue to switch on AC, Refrigerator, etc. You can shut down only the lamps of the house.

“Power Ministry, Power Grid Corporation of India (PGCIL) and the grid operator Power System Operator Corporation (POSOCO) are up to the task and are confident of managing the grid stability for the event”.

Stay Safe Stay at Home. 

#IndiaFightCorona. 

#KeepSocialDistancing 

“Sometimes you just need to go off the grid and get your soul right”

-Prashant Gorakhnath Patil

Read Your Electricity Bill

The Electric bill won't give you a Fright if you remember to Turn off the light.

It is the duty of the Electricity Supply Company (MSEDCL) to notify the periodicity of billing, date of meter reading, bill date and the due date for payment in a calendar month. The Company shall issue a bill to each consumer for the electricity. The bill is prepared on the basis of meter reading. In case the meter is not provided to a consumer the company shall prepare the bill based on the procedures approved by the Regulatory Commission.

Electricity Rate/Tariff: The rate at which Electrical Energy is supplied to the consumer is known as Electrical Tariff.

Electrical energy is a form of energy resulting from the flow of electric charge. Energy is the ability to do work or the ability to apply force to move an object.

Energy (E) = Power (P) X Time (t)

Unit: Watt-Hour (i.e. kWh/MWh/GWh)

Sample Bill (Source MSEDCL)

HSN Code (Top Right): 27160000 The main purpose of HSN is to classify goods from all over the World in a systematic and logical manner. This brings in a uniform classification of goods and facilitates international trade. It is developed by the WORLD CUSTOM ORGANIZATION (WCO). The Harmonized Commodity Description and Coding System generally refers to “Harmonized System of Nomenclature” or simply “HSN”.

The HSN structure contains 21 sections, with 99 Chapters, about 1,244 headings, and 5,224 subheadings. Each Section is divided into Chapters. Each Chapter is divided into Headings. Each Heading is divided into Sub Headings.

The HSN code chapter is represented in the first two digits of the HSN code.

In the given HSN Code 27 indicates: "Chapter 27: Mineral Fuels, Mineral Oils, and Products of their Distillation; Bituminous Substances; Mineral Waxes"

2716 is the subheading code that indicates: Electrical energy.

27160000: Bituminous mixtures based on natural asphalt, on natural bitumen, on petroleum bitumen, on mineral tar or on mineral tar pitch (for example, bituminous mastics, cutbacks): Electrical Energy.

Bill of Supply for: Shows the month and year of the generated bill i.e. the month of energy consumed.

Consumer No: This is the unique numeric number allotted to you by MSEDCL. This is the 12 digit number. Consumer number is the individual number allotted by the electricity board to the consumers at the time of a new connection. The electricity bill is prepared and sent to the consumers based on this consumer number only. Consumer number is useful when you book a grievance /complaint, you are required to give your consumer number. It can be used to pay electricity bills online.
Billing Unit: It is a four-digit number to identify the geographical location of your billing.
Name and Address: Bills are raised by MSEDCL on the name of a person who owns the premises. Name & Address gives the name of the consumer and address of his premises.
Sanctioned Load: Sanctioned Load means load in Kilowatt (kW) mutually agreed between MSEDCL and the consumer.
However, Sanctioned Load (or Contract Demand) are the correct indicators of the load imposed by a consumer and agreed to be delivered by the electricity supplier at any given point in time.
Bill Date: The date the bill was created.
The Bill shall be issued within FOUR days from the meter reading date and the bill date shall not be more than FOUR days from the meter reading date. In the case of spot billing, meter reading and bill date shall be the same.
Due Date: If the bill is not paid within this date additional charges for late payment will be applied in the given bill. Generally, additional charges are Rs 10.
Current Reading Date: The date on which 'current reading' is noted by the reader.
Security Deposit: Security Deposit is necessary because all consumer pay their bill after the consumption of electricity. They pay only after they receive a bill for their consumption in the previous month. They are also given a period of 10 to 15 days to pay the bill. Even if any consumer does not pay the bill, his supply can be cut only after serving him a notice and after giving a period of 15 days to make the payment. Thus a non – paying consumer can use electricity for about 2 months. To avoid losses in such cases, a security deposit equivalent to the electricity consumption of one month is collected from every monthly billed domestic consumer. This period may vary as per the duration of the billing.
Lately, MSEDCL has revised his tariff. So, an additional security deposit as per the revised tariff is necessary. It may also be mentioned here that MSEDCL pays interest on the security deposit of Rs. 50 or more at the rate equal to the post office saving bank rate as may be in the force from time to time.
Delayed Payment Charges (DPC): 
In case the electricity bills are not paid within the due date mentioned on the bill, delayed payment charges of 2 percent on the total electricity bill (including Taxes and Duties) shall be levied on the bill amount.

Fixed charges:
Fixed charges are levied to cover the fixed cost obligations of MSEDCL. Fixed charges cannot be based on the variable component of Tariff, the fixed charge is levied for only one month. A fixed charge is a part of the bill, which is the cost a consumer has to pay even if the person does not use any unit of power.
Security Deposit: As per the condition of supply, all State Electricity Boards are empowered to collect a security deposit from their consumers. Rs 1000 is a security deposit in the given case.

Energy charges:

Block Rate Tariff

Energy charges are calculated on the basis of how many units of energy you consume. Block rate tariff is used Energy consumed is measured and recorded by your meter, the energy company will subtract the amount shown on the previous meter reading from the most recent one to work out your bill.
Block rate tariff. When a given block of energy is charged at a specified rate and the succeeding blocks of energy are charged at progressively reduced rates, it is called a block rate tariff.
In block rate tariff, the energy consumption is divided into blocks and the price per unit is fixed in each block. The price per unit in the first block is the highest and it is progressively reduced for the succeeding blocks of energy. For example, the first 100 units may be charged at the rate of 03.05 Rs per unit; the next 200 units (101 to 300) at the rate of 06.95 Rs per unit and so on as shown in the picture.

Wheeling charges:

Wheeling charges are charged to transfer electrical power through transmission and distribution lines from one utility’s service area to another’s or It’s an amount charged by one electrical system to transmit the energy of, and for, another system. Wheeling charges are 1.28 Rs per unit.
Fuel Adjustment Cost (FAC) Charges:
The FAC charge will be determined based on the Formula and relevant directions, as may be given by the Commission from time to time and will apply to all consumer categories for their entire consumption.
The FAC Formula considers any change in the cost of own generation and power purchase due to variations in the fuel cost.
Fuel Price shall mean the landed cost of fuel at power station battery limits and will consist of only the following components:
a) Basic Fuel Price including statutory taxes, duties, royalty as applicable.
b) Transportation (freight) cost by rail/road/pipeline or any other means including transportation service charges for bringing fuel up to the Power Station.
c) Fuel Treatment Charges such as washing/cleaning charges, Sizing Crushing Charges, Fuel Analysis Charges, etc. for making fuel up to the required grade/quality.
d) Fuel Handling Charges, including that towards loading and unloading charges for bringing fuel to the power station.
Besides above, the Commission specifies a ceiling on “transportation service charge", at 2% of the freight charge.
The FAC charge shall be computed and levied/refunded, as the case may be every month.
The following formula shall be used for computing FAC:
FAC = C + I + B 
where,
FAC = Total Fuel Cost and Power Purchase Cost Adjustment,
C = Change in cost of own generation and power purchase due to variation in the fuel cost,
I = Interest on Working Capital,
B = Adjustment Factor for over-recovery/under-recovery.
The FAC will be charged every month in proportion to the variable charges of each category/consumption slab, and the details of the computation and recovery for the same will be submitted to the Commission for post-facto approval, every quarter.
Electricity Duty:
The Electricity Duty and Tax on Sale of Electricity will be charged in addition to charges levied as per the tariffs mentioned hereunder (as approved by the Commission) as per the Government guidelines from time to time.
Electricity Duty is 16% of the consumption charges.

Source: MSEDCL (21.10.2016)

Tax on Sale: The tax is to be paid by the power utility firm (for sale) to the government treasury after recovering it from consumers every month.
Arrears/Interest and Other Charges: Arrears is a financial and legal term that refers to the status of payments in relation to their due dates. If your electricity bill has old payment pending and interest on the same, or any other charges, then those will not match from the output of the tool to your electricity bill.
If your bills are pending for the previous months, and if you have not paid in the stipulated period, the amount of the pending bills is shown in the current bill as arrears. Sometimes if electricity boards increase the tariff from a retrospective date, and the board asks the consumers to pay in installments, and it will be shown as arrears.
Previous Bill Credit:
In case of duplicate/multiple payments and advance payment for a single bill, credit for the extra amount paid will be passed on in the subsequent bill.

The Less you Burn, the more you Earn.

-Prashant Gorakhnath Patil

Reference: MSEDCL

Thevenin's and Norton's Theorem

Thevenin's Theorem:

Thevenin’s Theorem is used to solve complicated electrical networks that cannot be solved by conventional methods. This theorem gives an organized approach to solve the given completed electrical network. This theorem also gives a technique by which the fixed part of the network is replaced by an equivalent circuit.

Statement: 

"Thevenin’s Theorem states that a linear two-terminal bilateral circuit can be replaced by an equivalent circuit consisting of a voltage source (V_Th) and source resistance (R_Th) connected in series. This series resistance is often called Thevenin Resistance."

Where V_Th is the open-circuit voltage at the terminals and R_Th is the input or equivalent resistance at the terminals when independent sources are inactive or turned off.

Inactive sources, Current Sources are short-circuited and Voltage Sources are open-circuited.

If the given circuit is AC then the circuit should be transformed to the frequency domain and Impedance (Z_Th) replaces resistance (R_Th)

 

Figure 1: Thevenin's Theorem

Conditions/Limitations:

1) Thevenin’s Theorem is not applicable to the circuits having unilateral elements like a diode etc.

2) Thevenin's Theorem is not applicable to the circuits that contain magnetic coupling between load and any circuit element.

3) Thevenin’s Theorem is not applicable to the circuits that contain nonlinear elements like transistors and diodes etc.

Steps to solve a given circuit using Thevenin's Theorem:

(Steps to Thevenize a given circuit)

1. Temporarily remove the load resistance R_L through which current is to calculate.

2. Find the open-circuit voltage (V_OC or V_ab or V_Th) across the two terminals a & b from where the load resistance has been removed. That is your Thevenin's Voltage V_Th. 

3. Calculate equivalent resistance between the same two terminals (a & b) by short-circuiting voltage source and open circuiting current sources (but keeping their internal resistances). This obtained equivalent resistance is called Thevenin Resistance (R_Th).

4. Now replace the entire network by a single voltage source V_Th and a resistance (R_Th) in series with it.

5. Connect the load resistance R_L back to the terminals a & b from where it is removed.

6. The obtained circuit is called Thevenin's Circuit.

7. Now calculate the current flowing through the load resistance R_Th

8. Finally, calculate the current flowing through the load resistance R_L by using Ohms Law:

I_L = V_Th/ (R_Th+R_L)

Figure: 1 a

Norton’s Theorem:

Edward Lawry Norton (28 July 1898, Rockland, Maine – 28 January 1983, Chatham, New Jersey) was an engineer and scientist. He worked at Bell Telephone Laboratory, USA and is known for Norton's Theorem. In 1926, about 43 years after Thevenin's Theorem, he proposed a dual of Thevenin's Theorem.

Statement:
"Norton’s Theorem states that a linear two-terminal bilateral circuit can be replaced by an equivalent circuit consisting of a current source (I_N) and source resistance (R_N) connected in parallel. This parallel resistance is called Norton Resistance and it is equal to Thevenin Resistance (R_Th)."
Where I_N is the short-circuit current through the terminals and R_N is the input or equivalent resistance at the terminals when independent sources are inactive or turned off.

Inactive sources, Current Sources are short-circuited and Voltage Sources are open-circuited.

If the given circuit is AC then the circuit should be transformed to the frequency domain and Impedance (Z_Th) replaces resistance (R_Th).

Conditions/Limitations: 

1) Norton’s Theorem is not applicable to the circuits having unilateral elements like diode etc.
2) Norton's Theorem is not applicable to the circuits that contain magnetic coupling between load and any circuit element.

3) Norton’s Theorem is not applicable to the circuits that contain nonlinear elements like transistors and diodes etc.

Figure 2: Norton's Theorem

Steps to solve a given circuit using Norton's Theorem:

(Steps to Nortonize a given circuit)

1. Temporarily remove the load resistance R_L (from a & b) through which current is to calculate and put short-circuit across them.

2. Find the short-circuit current I_sc.

3. Calculate equivalent resistance between the same two terminals (a & b) by the short-circuiting voltage source and open circuiting current sources (but keeping their internal resistances). This obtained equivalent resistance is called Norton Resistance (R_N = R_Th).

4. Now replace the entire network by a single current source I_N and a resistance (R_N) in parallel with it.

5. Connect the load resistance R_L back to the terminals a & b from where it is removed.

6. The obtained circuit is called Norton's Circuit.

7. Finally, calculate the current flowing through the load resistance R_L by using Current Division Rule:

I_L = I_N [R_N / (R_N+R_L)]

Figure: 2-a

Bilateral Network:

A circuit whose characteristic or behavior is same irrespective of the direction of current through various elements of it is called a bilateral network. 

A network consisting of only resistances is an example of a bilateral network.

Linear Network:

A linear circuit is an electric circuit in which circuit parameters (Resistance, inductance, capacitance, waveform, frequency, etc) are constant. 

In other words, a circuit whose parameters are not changed with respect to Current and Voltage is called Linear Circuit.

Three men are my friends - he that loves me, he that hates me and he that is indifferent to me. Who loves me, teaches me tenderness; who hates me, teaches me caution; who is indifferent to me, teaches me self-reliance.- J. E. Dinger