Technical indexes of DC power supply， DC power supplies
There are two technical indexes of DC power supply: one is characteristic index, including allowable input voltage, output voltage, output current and output voltage regulation range; the other is quality index, which is used to measure the stability of output DC voltage, including voltage stabilizing coefficient (or voltage regulation rate), output resistance (or current regulation rate), ripple voltage (surrounding and random drift).
1) Voltage stabilizing coefficient and voltage regulation rate: voltage stabilizing coefficient refers to the relative change of output voltage caused by the relative change of input voltage when the load current and ambient temperature remain unchanged. Voltage regulation rate refers to the relative change of output voltage when the relative change of input voltage is ± 10%. The voltage stabilizing coefficient and voltage regulation rate both explain the impact of input voltage change on output voltage, so only one of them needs to be tested.
2) Output resistance and current adjustment rate: the output resistance is the same as the output resistance of the amplifier, and its value is the absolute value of the ratio of the change of output voltage to the change of output current when the input voltage remains unchanged. Current regulation rate: the relative change of output voltage when the output current changes from 0 to the maximum value. Both the output resistance and current regulation rate show the influence of load current change on the output voltage, so only one of them needs to be tested.
3) Ripple voltage: AC voltage component superimposed on the output voltage. The peak and peak values observed by oscilloscope are generally in the order of millivolts. The effective value can also be measured by AC millivoltmeter, but there is a certain error because the ripple is not sine wave.
Application of DC power supply
The space industry bears a special national mission. Aerospace communication system has the characteristics of specificity and confidentiality, especially high timeliness requirements. The reliability of communication power supply is the primary consideration of aerospace communication department and an important guarantee for the safe operation of communication system. At present, the communication bureaus (stations) of the aerospace system generally use UPS system as the main power supply of IT equipment, which overcomes the system interruption caused by mains power interruption. However, the failure of UPS itself and even parallel redundant system leads to network communication accidents from time to time, which has had a great social impact and considerable economic losses.
As a simple and reliable technology, 240V high voltage DC power supply system (HVDC) reduces power conversion links and improves power supply reliability and efficiency. The aerospace communication department should actively track the development and changes of power supply technology, pay attention to the exploration results in application practice, convert new technologies into new applications, and improve the reliability level of aerospace communication system.
Advantages of 240V high voltage DC power supply system
240V high voltage DC power supply system has the advantages of mature technology, high reliability, simple maintenance and operation, high conversion efficiency and simple on-line capacity expansion. The communication industry has been discussing the use of high voltage DC system to replace UPS system.
240V HVDC power supply system has obvious technical and price advantages, and can be popularized and used on the premise of using the existing IT equipment. Therefore, it has been widely valued and supported by departments at all levels.
