Hybrid direct current transmission system and serial converter input device and method thereof

A power transmission system, hybrid DC technology, applied in power transmission AC network and other directions, can solve problems such as lack of versatility

CN109672206AInactive Publication Date: 2019-04-23NR ELECTRIC CO LTD +1
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2019-04-23
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a hybrid direct current transmission system and a serial converter input device and method thereof. The method comprises the steps of: controlling a thyristor converter required being input of a rectification convertor station to close a DC side isolating disconnecting link and an AC side incoming line switch to unlock the thyristor converter required being input and disconnect a DC side parallel bypass switch; controlling a voltage source type converter required being input of a inversion convertor station to close the DC side isolating disconnecting link and disconnect the AC side incoming line switch to access a charge resistor and connect an AC side bypass switch to perform pre-charge of the voltage source type converter required being input through the charge resistor, and connecting the AC side bypass switch after the pre-charge is completed; selecting a constant DC voltage control mode for unlocking to disconnect a DC side parallel bypass circuit; and finally, recovering the operation power of the hybrid direct current transmission system. The problems of online input of the hybrid converter are effectively solved to achieve online input of a serial VSC converter, reduce the AC-DC current impact when input and better protect the safety of the AC-DC transmission system.
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Description

technical field

[0001] The invention belongs to the field of hybrid direct current transmission, and in particular relates to a hybrid direct current transmission system and a device and method for inputting a series converter thereof. Background technique

[0002] HVDC systems can be divided into two types: conventional HVDC systems based on thyristor technology (LCC-HVDC) and flexible HVDC systems based on fully controlled voltage source converters (VSC-HVDC). Among them, the conventional direct current transmission system (LCC-HVDC) has the advantages of low cost, low loss, and mature operation technology. The station occupies a large area. The new generation of flexible DC transmission system has the advantages of decoupling control of active power and reactive power, power supply to passive network, compact structure, small footprint, and no commutation failure on the inverter side. There are defects such as high cost and large loss. In recent years, the hybrid DC tr...

Examples

Embodiment 1

[0117] The method for putting the converter into operation is to perform the following steps when it is detected that the hybrid direct current transmission system needs to be put into operation for the converter:

[0118] (1) Control the rectifier converter station to increase the firing angle, and control the DC voltage of the inverter converter station to decrease to the range that allows the converter to be put into operation;

[0119] (2) To control the thyristor converters that need to be put into operation in the rectification converter station, perform the following two operations, and the operation sequence of the two operations is not in particular order:

[0120] (a2) Close the DC side isolation switch;

[0121] (b2) close the AC side incoming line switch;

[0122] (3) To control the thyristor converters that need to be put into operation in the rectification converter station, perform the following two parts of operations, and the operation sequence of the two par...

Embodiment 2

[0134] The method for putting the converter into operation is to perform the following steps when it is detected that the hybrid direct current transmission system needs to be put into operation for the converter:

[0135] (21) Control the rectifier converter station to increase the firing angle, and control the DC voltage of the inverter converter station to reduce to the range that allows the converter to be put into operation;

[0136] (22) To control the voltage source converters that need to be put into the inverter converter station, perform the following three operations. The operation sequence of the three operations is not in particular order:

[0137] (a22) Close the DC side isolation switch;

[0138] (b22) Select STATCOM operation mode or DC operation mode;

[0139] (c22) Disconnect the bypass switch on the AC side, connect the charging resistor to the AC line; close the AC incoming switch, and pre-charge the voltage source converter that needs to be put into the inv...

Embodiment 3

[0159] The control unit specifically performs the following steps when the discrimination unit detects that the hybrid direct current transmission system needs to put the converter into operation:

[0160] (1) Control the rectifier converter station to increase the firing angle, and control the DC voltage of the inverter converter station to decrease to the range that allows the converter to be put into operation;

[0161] (2) To control the thyristor converters that need to be put into operation in the rectification converter station, perform the following two operations, and the operation sequence of the two operations is not in particular order:

[0162] (a2) Close the DC side isolation switch;

[0163] (b2) close the AC side incoming line switch;

[0164] (3) To control the thyristor converters that need to be put into operation in the rectification converter station, perform the following two parts of operations, and the operation sequence of the two parts is in no parti...