How does the output ripple voltage of Din-rail power supply change under different load conditions?
Publish Time: 2024-10-30
The output ripple voltage of Din-rail power supply shows a certain change pattern under different load conditions:
1. When no-load or light load:
The ripple voltage is relatively small: When no-load or the load current is very small, the output ripple voltage of Din-rail power supply is at a low level. This is because the power devices inside the power supply are working in a relatively relaxed state at this time, the current changes relatively slowly, and the charging and discharging of energy storage components such as capacitors are less affected. For example, some high-precision Din-rail power supplies may have a ripple voltage of only a few millivolts or even lower when no-loaded.
The high-frequency component may increase: Although the overall ripple voltage is small, some parasitic parameters in the circuit and the high-frequency characteristics of the components are more prominent when lightly loaded, which may increase the high-frequency component in the ripple. This part of the high-frequency ripple may be caused by the interaction between the inductor, capacitor and other components in the circuit and the high-frequency switching action of the switching device.
2. Medium load:
Ripple voltage is relatively stable: When the load of the Din-rail power supply is at a medium level, the working state of the power supply is relatively stable, and the ripple voltage is also in a relatively stable state. At this time, the output current of the power supply can fully charge and discharge energy storage elements such as capacitors, thereby suppressing the ripple to a certain extent. For example, in some industrial automation equipment, the ripple voltage of the Din-rail power supply can be kept within a relatively fixed range under normal working load to meet the normal operation requirements of the equipment.
Proportional relationship with load current: Within a certain range, the magnitude of the ripple voltage may increase slightly with the increase of load current. This is because as the load current increases, the power loss inside the power supply increases, and the voltage fluctuation in the circuit will also increase accordingly, resulting in an increase in the ripple voltage. However, this upward trend is usually slow and is acceptable within the design range of the power supply.
3. Full load or overload:
Ripple voltage increases significantly: When the Din-rail power supply approaches or reaches full load, or even in an overload state, the ripple voltage will increase significantly. This is because under high load conditions, the power devices inside the power supply are subjected to large current and voltage stresses, and the frequency and amplitude of the switching action may change, resulting in an increase in the fluctuation of the output voltage. At the same time, the charging and discharging speed of energy storage components such as capacitors cannot keep up with the demand of the load, and the voltage fluctuation cannot be effectively smoothed, causing a significant increase in the ripple voltage. For example, if the rated load of a Din-rail power supply is 10A, when the load current approaches or exceeds 10A, the ripple voltage may increase several times or even higher.
Abnormal fluctuations may occur: Under extreme overload conditions, the Din-rail power supply may experience abnormal voltage fluctuations, and may even trigger protection mechanisms such as overcurrent protection. Such abnormal fluctuations will not only affect the normal output of the power supply, but may also cause damage to the connected load equipment.
In short, the variation law of the output ripple voltage of the Din-rail power supply under different load conditions is complex, and is affected by many factors such as the design of the power supply itself, component parameters, and load characteristics. In practical applications, it is necessary to select a suitable Din-rail power supply according to the specific load conditions, and monitor and control the ripple voltage to ensure the normal operation of the equipment.
