Electrical assembly

Patent metadata

Field	Value
Publication number	US-10389130-B2
Application number	US-201716081092-A
Country	US
Kind code	B2
Filing date	Feb 23, 2017
Priority date	Feb 29, 2016
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

An electrical assembly includes a power converter having first and second DC terminals which are connectable to a DC electrical network. The power converter also includes converter limbs connected between the first and second DC terminals. Each converter limb includes an AC terminal that is connectable to a respective AC phase of a multi-phase AC electrical network. Each converter limb also includes limb portions, each connected between a corresponding AC terminal and a respective one of the first and second DC terminals. Each limb portion includes switching element(s). The electrical assembly includes a single grounding circuit having a reactor configured to provide a current path for alternating current with a high impedance to ground and a current path for direct current with a low impedance to ground. The grounding circuit is arranged so that only one of the AC phases is connected to ground via the grounding circuit.

First claim

The invention claimed is:

1. An electrical assembly comprising:
a power converter including:
first and second DC terminals connectable to a DC electrical network;
a plurality of converter limbs connected between the first and second DC terminals, each converter limb including:
a respective AC terminal connectable to a respective AC phase of a multi-phase AC electrical network; and
first and second limb portions, each limb portion connected between the corresponding AC terminal and a respective one of the first and second DC terminals, each limb portion including at least one switching element;

wherein the electrical assembly includes a single grounding circuit that includes a reactor configured to provide a current path for alternating current with a high impedance to ground and a current path for direct current with a low impedance to ground, the grounding circuit being arranged so that only one of the AC phases is connected to ground via the grounding circuit.

2. An electrical assembly according to claim 1 , wherein the grounding circuit further includes a resistor connected with the reactor.

3. An electrical assembly according to claim 2 , wherein the resistor is configured to damp oscillations present between the capacitance of the power converter and/or capacitance of a power transmission medium connected to the power converter and the inductance of the grounding circuit.

4. An electrical assembly according to claim 1 , wherein at least one of the limb portions includes at least one module, the or each module including a plurality of switching elements and at least one energy storage device, each switching element and the or each energy storage device in the or each module arranged to be combinable to selectively provide a voltage source.

5. An electrical assembly according to claim 4 , wherein at least one of the limb portions of each converter limb includes a plurality of series-connected modules.

6. An electrical assembly according to claim 4 , wherein the or each module includes a pair of switching elements connected in parallel with an energy storage device in a half-bridge arrangement to define a 2-quadrant unipolar module that can provide a zero or positive voltage source and can conduct current in two directions.

7. An electrical assembly according to claim 4 , wherein the or each module includes two pairs of switching elements connected in parallel with an energy storage device in a full-bridge arrangement to define a 4-quadrant bipolar module that can provide a negative, zero or positive voltage and can conduct current in two directions.

8. An electrical assembly according to claim 1 , wherein the power converter includes three converter limbs, the respective AC terminal of each converter limb being connectable to a respective phase of a three-phase AC electrical network.

Assignees

• General Electric Technology Gmbh

Inventors

• Gupta Robin
• Whitehouse Robert

Classifications

• H02M7/7575

  for high voltage direct transmission link · CPC title

• Y02E60/60

  Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD] · CPC title

• H02M7/003

  Constructional details, e.g. physical layout, assembly, wiring or busbar connections · CPC title

• H02J3/36 Primary

  Arrangements for transfer of electric power between AC networks via high-voltage DC [HVDC] links; Arrangements for transfer of electric power between generators and networks via HVDC links · CPC title

• H02J2003/365

  Reducing harmonics or oscillations in HVDC · CPC title