Power supply power distribution system and method

[0031] Example 1

[0032] As attached image 3 , Attached Figure 4 , Attached Figure 5 As shown, the power distribution system of this embodiment includes a 24-pulse rectifier circuit 1 and a DC/DC power supply 2 installed on the electrical equipment. The 24-pulse rectifier circuit 1 includes two 12-pulse axial double splits Type rectifier transformer 3 and four sets of full-wave rectifier bridges 4. The 24-pulse rectifier circuit 1 is connected to the DC/DC power supply 2 through a DC transmission line. The DC/DC power supply 2 includes an LC filter circuit, an IGBT inverter circuit, Step-down circuit and diode rectifier filter circuit.

[0033] This embodiment also provides a new power distribution method based on the above-mentioned power distribution system. image 3 As shown, the three-phase 35kV high-voltage power from the power grid is connected to the 24-pulse rectifier circuit 1, and after the step-down rectification in the 24-pulse rectifier circuit 1, the direct current is directly output for use by electrical equipment. As attached Figure 4 As shown, the 24-pulse rectifier circuit 1 includes two 12-pulse axial double-split rectifier transformers 3 and four sets of full-wave rectifier bridges 4, and each 12-pulse axial double-split rectifier transformer 3 has two sets of windings on the valve side. They are connected into d connection and y connection respectively, so that the line voltage naturally forms a phase difference of 30°. The grid sides of the two 12-pulse axial double split rectifier transformers 3 adopt the Yanbian delta connection, and the phase shift is ±7.5. °, the two rectifier transformers have a phase difference of 15° between the line voltage phases of the four sets of valve-side windings. Each winding runs in parallel on the DC side after full-wave rectification.

[0034] The 24-pulse rectifier circuit 1 of this embodiment combines a previously separate distribution transformer and a rectifier circuit. After the 35kV high voltage from the power grid is connected to the 24-pulse rectifier circuit 1, the two 12-pulse axial double The split-type rectifier transformer 3 steps down, and then is rectified by four sets of full-wave rectifier bridges 4 to output DC power for use by electrical equipment. DC transmission reduces the number of transmission cables between power distribution equipment and electrical equipment, and only two A power cable; In addition, by increasing the output voltage of the 24-pulse rectifier circuit 1, under the condition of a certain transmission power, a higher DC output voltage can greatly reduce the current on the transmission cable, thereby reducing the transmission cable The direct benefit brought to the enterprise is that it reduces the amount of metal materials such as copper and aluminum on the transmission line. In addition, there is no AC inductance loss in DC transmission, which can reduce the power loss on the transmission line. Since the power distribution equipment and the electrical equipment adopt the DC route, the backup battery of the corresponding electrical equipment can also be configured as a DC UPS. The DC UPS has a simple structure, small footprint, low cost and high stability.

[0035] The 24-pulse rectifier circuit 1 includes two 12-pulse axial double-split rectifier transformers 3 and four sets of full-wave rectifier bridges 4. Each 12-pulse axial double-split rectifier transformer 3 is connected to two sets of windings on the valve side. d connection and y connection, the grid side of the two 12-pulse axial double split rectifier transformers 3 adopts the Yanbian delta connection. Due to the special connection between the valve side and the grid side of the rectifier transformer, the grid-side current harmonic distortion rate of the 24-pulse rectifier circuit 1 is only 6.3%, so there is no need to install harmonic control equipment at the power input end of the electrical equipment. The cost of this part of the equipment is reduced, and there is no efficiency loss caused by the harmonic control equipment, which improves the system efficiency. The ripple of the DC power obtained by the 24-pulse rectifier circuit 1 is extremely small, which can greatly reduce the capacitance of the LC filter circuit in the DC/DC power supply 2, thereby reducing costs and improving reliability.

[0036]