Explanation of odd harmonic

How does the odd harmonics be generated?

1. Square Wave Signals: As explained earlier, when a square wave is synthesized or processed in electronic circuits, it naturally contains odd harmonics of the fundamental frequency due to its shape and Fourier series composition.

2. Clipping in Amplifiers: When an amplifier is overdriven and hits the limits of its supply voltage, the tops of the waveforms (both positive and negative) are clipped off, which introduces a broad spectrum of harmonics. Because the clipping creates a waveform that more closely resembles a square wave, odd harmonics are especially prominent.

3. Switching Devices: In power electronics, devices such as transistors and thyristors switch on and off rapidly, creating pulse-width modulated signals and other square-like waveforms that contain odd harmonics due to their sharp transitions and non-linear operation.

4. Rectifiers: In the process of converting AC to DC, rectifiers can introduce harmonics due to the non-linear conduction intervals. For single-phase rectifiers, the output waveform is a series of pulses with a fundamental frequency twice that of the input AC, along with a series of odd harmonics.

5. Saturable Reactors and Magnetic Cores: When inductors or transformers operate in a region where the magnetic core material begins to saturate, the relationship between the magnetic field (B) and the magnetizing force (H) becomes non-linear, producing odd harmonics in the current waveform.

6. Electric Motors: Under certain conditions, like when there is an asymmetry in the winding, uneven air gap, or the supply voltage has harmonics, electric motors can generate odd harmonics in their current and voltage waveforms.

7. Arcing Devices: Electrical arcing in switches, contacts, and circuit breakers introduces non-linearity into the circuit, which can generate a wide range of harmonics, including odd harmonics.

8. Non-Linear Loads: Devices that draw a non-linear current from a linear voltage supply, such as certain types of power supplies, fluorescent lighting with magnetic ballasts, and some types of heating elements, can introduce odd harmonics back into the power system.

Jeopardize of the odd harmonics

1. Efficiency Loss: Harmonics can cause additional I²R losses in power systems because they increase the RMS (Root Mean Square) current in electrical conductors without contributing to the useful power. This extra current results in wasted energy and can lead to higher utility bills.

2. Overheating: Harmonics can cause excessive heating in electrical components such as transformers, motors, and cables. This not only reduces their lifespan but can also lead to insulation failure and increase the risk of fire.

3. Equipment Malfunction: Sensitive electronic equipment can malfunction or fail when exposed to harmonic distortion. The distorted waveforms can interfere with the proper operation of control systems, protective relays, and other electronic devices.

4. Reduced Power Factor: The presence of harmonics reduces the overall power factor of the system. This is because harmonic currents do not do any real work but still contribute to the total power drawn from the source. A poor power factor may lead to penalties from power companies and require the installation of power factor correction equipment.

5. Resonance: Odd harmonics can interact with the natural resonant frequencies of the power system components, leading to resonant conditions. Resonance can greatly amplify the distortion and lead to voltage and current spikes, causing damage to the system.

6. Interference with Communication Systems: Harmonic frequencies can interfere with communication lines that run parallel to power cables, leading to noise and errors in the communication systems.

7. Metering Errors: Harmonic distortion can cause inaccuracies in metering equipment, leading to incorrect measurement of power consumption.

8. Capacitor Bank Failure: Capacitor banks used for power factor correction can be particularly vulnerable to harmonics, which can cause them to overheat, age prematurely, and even fail due to excessive currents at harmonic frequencies.

9. Conductor and Connection Stress: The additional current from harmonics can lead to thermal expansion and contraction in conductors and connections, causing mechanical stress and potentially leading to loose connections or breaks over time.

10. EMI (Electromagnetic Interference): Harmonics contribute to electromagnetic interference, which can affect other nearby electrical and electronic equipment.