To make the supply voltage constant in inverters, a capacitor is connected in parallel to the supply side. This helps to stabilize the voltage and reduce any fluctuations that may occur during the operation of the inverter.

Explanation:
Inverters are electronic devices used to convert DC (direct current) power into AC (alternating current) power. They are commonly used in various applications such as solar power systems, uninterruptible power supplies (UPS), and motor drives.

During the operation of an inverter, the input DC voltage is converted into an AC voltage with a specific frequency and amplitude. However, due to various factors such as load variations, changes in input voltage, and switching actions, the output voltage of the inverter may have fluctuations or variations.

To ensure a stable and constant supply voltage, a capacitor is connected in parallel to the supply side of the inverter. This capacitor acts as a filter and helps to smooth out any voltage ripples or variations that may occur in the system.

Here are the reasons why a capacitor is connected in parallel to the supply side:

1. Filtering the Voltage:
The capacitor acts as a low-pass filter, allowing the AC component of the voltage to pass through while blocking any high-frequency or rapid changes in voltage. This helps to remove any voltage ripples or variations caused by switching actions or load changes.

2. Stabilizing the Voltage:
By smoothing out the voltage waveform, the capacitor helps to stabilize the supply voltage and ensures a more constant and reliable output. This is particularly important in applications where a stable voltage is required, such as sensitive electronic equipment or precision motor control systems.

3. Improving Power Quality:
The presence of a capacitor in the inverter helps to improve the power quality by reducing harmonic distortion and improving the power factor. Harmonics are unwanted frequencies that can cause issues such as overheating in electrical systems or interference with other devices. The capacitor helps to mitigate these harmonics and improve the overall power quality.

In conclusion, connecting a capacitor in parallel to the supply side of an inverter is an effective way to make the supply voltage constant. This helps to stabilize the voltage, reduce fluctuations, and improve the overall performance and reliability of the inverter system.