阅读说明：本技术 Hvdc功率转换器中或者与其相关的改进 (Improvements in or relating to HVDC power converters ) 是由 S·卡布尔 A·阿当齐克 于 2019-02-12 设计创作，主要内容包括：在高压直流(HVDC)功率转换器的领域中,提供有一种HVDC功率转换器(10),该HVDC功率转换器(10)包括第一和第二DC端子(12,14),所述第一和第二DC端子(12,14)用于到DC网络(20)的对应的第一和第二DC传输管道(16,18)的连接。功率转换器(10)还包括至少一个转换器分支(22A,22B,22C),所述至少一个转换器分支(22A,22B,22C)在第一与第二DC端子(12,14)之间延伸。所述或每个转换器分支(22A,22B,22C)包括通过相应的AC端子(30A,30B,30C)所分离的第一和第二分支部分(26A,28A,26B,28B,26C,28C)。所述或每个转换器分支(22A,22B,22C)的AC端子(30A,30B,30C)用于到AC网络(24)的相应相(a,b,c)的连接。所述或每个第一分支部分(26A,26B,26C)在第一DC端子(12)与对应的AC端子(30A,30B,30C)之间延伸,而所述或每个第二分支部分(28A,28B,28C)在第二DC端子(14)与对应的AC端子(30A,30B,30C)之间延伸。分支部分(26A,28A,26B,28B,26C,28C)各自包括相应阀(32),所述相应阀(32)在功率转换器(10)的正常使用期间相互协作操作,以便在DC与AC网络(20,24)之间传递功率。至少一个第一分支部分(26A,26B,26C)指定为第一传递分支部分(34),而至少一个第二分支部分(28A,28B,28C)指定为第二传递分支部分(36)。另外,功率转换器(10)包括至少一个传递电感器(60),所述至少一个传递电感器(60)电连接在传递分支部分(34,36)与接地(62)之间。功率转换器(10)更进一步包括控制单元(80),该控制单元(80)被编程为当在管道能量传递模式中操作功率转换器(10)的同时：(a)在第一操作循环期间引导电流经由所述或每个第一传递分支部分(34)或者所述或每个第二传递分支部分(36)的对应的一个传递分支部分从所述第一DC端子(12)或所述第二DC端子(14)中的一个DC端子流动到一个或多个传递电感器(60),由此能量从DC传输管道(16,18)传递给一个或多个传递电感器(60),所述DC传输管道(16,18)在使用中与第一DC端子(12)或第二DC端子(14)的所述一个DC端子连接；以及(b)在第二操作循环期间引导电流经由所述或每个第一传递分支部分(34)和所述或每个第二传递分支部分(36)的对应的另一个传递分支部分从一个或多个传递电感器(60)流动到第一DC端子(12)和第二DC端子(14)的另一个DC端子,由此能量从一个或多个传递电感器(60)传递给DC传输管道(16,18),所述DC传输管道(16,18)在使用中与第一DC端子(12)和第二DC端子(14)的所述另一个DC端子连接。(In the field of High Voltage Direct Current (HVDC) power converters, there is provided an HVDC power converter (10), the HVDC power converter (10) comprising first and second DC terminals (12, 14), the first and second DC terminals (12, 14) being for connection to corresponding first and second DC transmission conduits (16, 18) of a DC network (20). The power converter (10) further comprises at least one converter branch (22A, 22B, 22C), the at least one converter branch (22A, 22B, 22C) extending between the first and second DC terminals (12, 14). The or each converter limb (22A, 22B, 22C) comprises first and second limb portions (26A, 28A, 26B, 28B, 26C, 28C) separated by a respective AC terminal (30A, 30B, 30C). The AC terminals (30A, 30B, 30C) of the or each converter limb (22A, 22B, 22C) are for connection to respective phases (a, B, C) of an AC network (24). The or each first limb portion (26A, 26B, 26C) extends between the first DC terminal (12) and the corresponding AC terminal (30A, 30B, 30C), and the or each second limb portion (28A, 28B, 28C) extends between the second DC terminal (14) and the corresponding AC terminal (30A, 30B, 30C). The branch portions (26A, 28A, 26B, 28B, 26C, 28C) each include a respective valve (32), the respective valves (32) operating in cooperation with one another during normal use of the power converter (10) to transfer power between the DC and AC networks (20, 24). At least one first branch portion (26A, 26B, 26C) is designated as a first transfer branch portion (34) and at least one second branch portion (28A, 28B, 28C) is designated as a second transfer branch portion (36). In addition, the power converter (10) includes at least one transfer inductor (60), the at least one transfer inductor (60) being electrically connected between the transfer limb portions (34, 36) and ground (62). The power converter (10) further comprises a control unit (80), the control unit (80) being programmed to, while operating the power converter (10) in the pipeline energy transfer mode: (a) directing current to flow from one of the first or second DC terminals (12, 14) to one or more transfer inductors (60) via a corresponding one of the or each first transfer limb portion (34) or the or each second transfer limb portion (36) during a first cycle of operation whereby energy is transferred from a DC transfer duct (16, 18) to the one or more transfer inductors (60), the DC transfer duct (16, 18) being connected in use with the one of the first or second DC terminals (12, 14); and (b) directing current to flow from the one or more transfer inductors (60) to the other of the first and second DC terminals (12, 14) via the corresponding other of the or each first transfer limb portion (34) and the or each second transfer limb portion (36) during a second operating cycle, whereby energy is transferred from the one or more transfer inductors (60) to the DC transfer ducts (16, 18), the DC transfer ducts (16, 18) being connected in use with the other of the first and second DC terminals (12, 14).)

1. An HVDC power converter (10) comprising:

first and second DC terminals (12, 14), the first and second DC terminals (12, 14) for connection to corresponding first and second DC transmission conduits (16, 18) of a DC network (20);

at least one converter limb (22A, 22B, 22C), the or each converter limb (22A, 22B, 22C) extending between the first and second DC terminals (12, 14), the or each converter limb (22A, 22B, 22C) comprising first and second limb portions (26A, 28A, 26B, 28B, 26C, 28C) separated by a respective AC terminal (30A, 30B, 30C), the AC terminals (30A, 30B, 30C) of the or each converter limb (22A, 22B, 22C) being for connection to respective phases (a, B, C) of an AC network (24), the or each first limb portion (26A, 26B, 26C) extending between the first DC terminal (12) and a corresponding AC terminal (30A, 30B, 30C), the or each second limb portion (28A, 28B, 28C) extends between the second DC terminal (14) and a corresponding AC terminal (30A, 30B, 30C), the limb portions (26A, 28A, 26B, 28B, 26C, 28C) each comprising a respective valve (32), the respective valves (32) operating in cooperation with one another during normal use of the power converter (10) to transfer power between the DC and AC networks (20, 24), at least one first limb portion (26A, 26B, 26C) being designated as a first transfer limb portion (34) and at least one second limb portion (28A, 28B, 28C) being designated as a second transfer limb portion (36);

at least one transfer inductor (60), the at least one transfer inductor (60) electrically connected between the transfer limb portion (34, 36) and ground (62); and

a control unit (80), the control unit (80) being programmed to, while operating the power converter (10) in a pipeline energy transfer mode:

(a) directing current to flow from one of the first or second DC terminals (12, 14) to one or more transfer inductors (60) via a corresponding one of the or each first transfer limb portion (34) or the or each second transfer limb portion (36) during a first cycle of operation whereby energy is transferred from the DC transfer duct (16, 18) to the one or more transfer inductors (60), the DC transfer duct (16, 18) being connected in use with the one of the first or second DC terminals (12, 14); and

(b) directing current to flow from the one or more transfer inductors (60) to the other of the first and second DC terminals (12, 14) via the corresponding other of the or each first transfer limb portion (34) and the or each second transfer limb portion (36) during a second cycle of operation, whereby energy is transferred from the one or more transfer inductors (60) to the DC transfer ducts (16, 18), the DC transfer ducts (16, 18) being connected in use with the other of the first and second DC terminals (12, 14).

2. The power converter (10) of claim 1 wherein the control unit (80) is programmed to:

(a) directing current to flow from a DC terminal (12, 14) to one or more transfer inductors (60) via a corresponding one of the or each first transfer limb portion (34) and the or each second transfer limb portion (36) during the first operating cycle, whereby energy is transferred from the DC transfer duct (16, 18) carrying the higher voltage to the one or more transfer inductors (60), the DC terminal (12, 14) being connected in use with the DC transfer duct (16, 18) carrying the higher voltage; and

(b) directing current to flow from the one or more transfer inductors (60) to the DC terminals (12, 14) via a corresponding other of the or each first transfer limb portion (34) and the or each second transfer limb portion (36) during the second operating cycle, whereby energy is transferred from the one or more transfer inductors (60) to the DC transfer ducts (16, 18) carrying the lower voltage, the DC terminals (12, 14) being connected in use with the DC transfer ducts (16, 18) carrying the lower voltage.

3. The power converter (10) of claim 2 wherein the control unit (80) is programmed to operate the power converter (10) in the pipe energy transfer mode after a fault condition in which, in use, the voltage carried by one DC transmission pipe (16, 18) decreases and the voltage carried by the other DC transmission pipe (16, 18) increases.

4. The power converter (10) of claim 3 wherein the control unit (80) is programmed to block each valve (32) to prevent transfer of power between the DC and AC networks (20, 24) when the power converter (10) is operated in the pipe energy transfer mode after a failed pipe as a first step.

5. The power converter (10) of any preceding claim wherein the control unit (80) is programmed to repeat the first and second cycles of operation.

6. The power converter (10) of any preceding claim wherein the or each AC terminal (30A, 30B, 30C) is connected to a first transformer winding (64) of a transformer (66), the transformer (66) being configured to connect the power converter (10) to an AC network (24) in use.

7. The power converter (10) of claim 6 wherein a transfer inductor (60) extends between a neutral point (68) of the first transformer winding (64) and ground (62).

8. The power converter (10) of any preceding claim wherein at least one transfer inductor (60) takes the form of a dedicated inductive component (72) configured only to handle transfer of energy between respective DC transfer conduits (16, 18) in use.

9. The power converter of claim 8, wherein the or each dedicated inductive component (72) is arranged in series with a switch (78), and the control unit (80) is further programmed to close the or each switch (78) while operating the power converter (10) in the pipeline energy transfer mode, so as to place the corresponding inductive component (72) in circuit between the transfer branch portion (34, 36) and ground (62).

10. A power converter (10) as claimed in any preceding claim in which each transfer limb portion (34, 36) comprises a valve (32) in the form of a transfer valve (38), the valve (32) selectively allowing current (I |)₁) Flows in a first direction (D1) while always allowing a current (I)₂) Flows therethrough in a second direction (D2), the second direction (D2) being opposite the first direction (D1).

11. The power converter (10) of any of claims 1 to 9 wherein each transfer limb portion (34, 36) includes a valve (32) in the form of a transfer valve (38), wherebyThe valve (32) selectively allowing current (I)₁) Flows in a first direction (D1) while selectively allowing only the current (I)₂) Flows therethrough in a second direction (D2), the second direction (D2) being opposite the first direction (D1).