**What is Energy Meter?**

**Construction of Single-Phase Induction Type Energy Meter:**

- Driving system
- Moving system
- Braking system
- Registering system

**1. Driving System:**

**2. Moving System:**

**3. Braking System:**

**4. Registering System:**

**Working of Single-Phase Induction Type Energy Meter:**

**Torque Equation of single Phase energy Meter:**

∴ T ∝ Î¦_{p}I_{se}CosÎ¦
- Î¦_{se}I_{p} cos (180 – Î¦)

Where T = average torque produced in the disc

Î¦_{p} = alternating flux links with the disc

I_{se} = Eddy current
flowing through the series

Where Cos(180-Î¦) = -cosÎ¦ put this in above formula

Above Formula become

∴ T ∝ Î¦_{p}I_{se}CosÎ¦
_{+} Î¦_{se}I_{p} cosÎ¦

∴ T ∝ CosÎ¦ (Î¦_{p}I_{se}
_{+} Î¦_{se}I_{p} )

But given that

∴ I_{p} ∝ Î¦_{p}
∝ V_{ph}

∴ I_{se} ∝ Ï†_{se}
∝ I_{L}

From This

∴ Î¦_{p}I_{se } ∝ V_{ph} I_{L} = Î¦_{p}I_{se} =A V_{ph}
I_{L }and

∴ Î¦_{p}I_{se} ∝ V_{ph}
I_{L} = Î¦_{p}I_{se}
= B V_{ph} I_{L}

∴ T ∝ (A V_{ph}
I_{L }+ B V_{ph}
I_{L}) cosÎ¦

∴ T ∝ (A + B ) V_{ph} I_{L }cosÎ¦

Where A + B = Constant

∴ T ∝ V_{ph} I_{L }cosÎ¦

In an energy meter, the average torque produced in the disc
is used to measure the power consumed in the load.

The torque produced by the braking magnet (TB) is also
proportional to the speed of the disc (N). The braking magnet applies a force
to the disc to slow it down or stop it from rotating, and the strength of this
force is influenced by the speed of the disc. As the disc speeds up, the
braking magnet must apply a stronger force to bring the disc to a stop.

∴ T_{B} ∝ N

∴ T_{B} = K_{2} N

∴ T ∝ V_{ph} I_{L }cosÎ¦

∴ T = K_{1}
V_{ph} I_{L }cosÎ¦

In a steady-state condition, the braking torque and the
driving torque of an energy meter should be equal.

∴ T_{B} = T

∴ K_{2} N = K_{1} V_{ph} I_{L }cosÎ¦

∴ N = K_{1}/ K_{2} V_{ph} I_{L }cosÎ¦

∴ N = True power of the circuit

**Advantages of Induction Type Energy Meter:**

**Long lifespan with low maintenance:**Induction type energy meters are known for their long lifespan and low maintenance requirements. They can be used for extended periods of time without needing frequent repairs or maintenance.**Inexpensive:**Induction type energy meters are generally less expensive than other types of energy meters, making them a cost-effective choice for many applications.**High torque-to-weight ratio:**The induction type energy meter has a high torque-to-weight ratio, which means that it is able to produce a lot of torque while still being relatively lightweight. This makes it suitable for a wide range of applications.

**Disadvantages of Induction Type Energy Meter:**

**Sensitive to adjustments:**If the meter is not properly adjusted, it can introduce large errors in the readings. This can affect the accuracy of the energy measurement.**Limited to ac measurement:**The principle of induction that is used in induction type energy meters can only be applied to alternating current (ac) measurements. This means that these meters are not suitable for measuring direct current (dc) energy consumption.**Wide range of load measurement:**Induction type energy meters are able to measure energy over a wide range of loads, making them suitable for use in a variety of different environments and applications.