Circuit arrangement for a photovoltaic inverter for break relief using short-circuit switches, and uses of the circuit arrangement

Patent metadata

Field	Value
Publication number	US-2016226256-A1
Application number	US-201615072761-A
Country	US
Kind code	A1
Filing date	Mar 17, 2016
Priority date	Sep 17, 2013
Publication date	Aug 4, 2016
Grant date	—

Abstract

A circuit arrangement for a photovoltaic inverter includes two bus lines, input terminals for connecting at least one photovoltaic generator to the bus lines, respectively, and at least one DC/AC converter connected to the bus lines. The circuit arrangement further includes a disconnector between each DC/AC converter and the bus lines, respectively, and at least one short-circuit path for short-circuiting a voltage between the bus lines, wherein a short-circuit switch is arranged in the short-circuit path, wherein the at least one short-circuit path runs between the bus lines upstream of all disconnectors between the input terminals and the disconnectors, and wherein the short-circuit switch in the at least one short-circuit path between the bus lines is connected in series with a fuse. Still further, the circuit arrangement includes at least one further short-circuit path for short-circuiting the voltage between the bus lines, wherein a short-circuit switch likewise is arranged in the at least one further short-circuit path

First claim

1 . A circuit arrangement for a photovoltaic inverter, comprising:
two bus lines; input terminals for connecting at least one photovoltaic generator to the bus lines, respectively; at least one DC/AC converter connected to the bus lines; a disconnector between each DC/AC converter and the bus lines, respectively; at least one short-circuit path for short-circuiting a voltage between the bus lines, wherein a short-circuit switch is arranged in the short-circuit path, wherein the at least one short-circuit path runs between the bus lines upstream of all disconnectors between the input terminals and the disconnectors, and wherein the short-circuit switch in the at least one short-circuit path between the bus lines is connected in series with a fuse; and at least one further short-circuit path for short-circuiting the voltage between the bus lines, wherein a short-circuit switch likewise is arranged in the at least one further short-circuit path.

2 . The circuit arrangement as claimed in claim 1 , wherein the short-circuit switches in one or more of the short-circuit paths are thyristors.

3 . The circuit arrangement as claimed in claim 1 , wherein the short-circuit switch in the at least one short-circuit path between the bus lines is furthermore connected in series with a current-limiting component.

4 . The circuit arrangement as claimed in claim 1 , wherein the at least one further short-circuit path runs between the connection lines of the at least one DC/AC converter, and is connected to the connection lines downstream of the disconnector between the disconnector and the at least one DC/AC converter.

5 . The circuit arrangement as claimed in claim 4 , wherein at least two DC/AC converters are connected to the bus lines, and downstream of at least two of the disconnectors of the at least two DC/AC converters in each case one of the further short-circuit paths runs between the connection lines of the associated DC/AC converter.

6 . The circuit arrangement as claimed in claim 4 , wherein downstream of each disconnector one of the further short-circuit paths runs between the connection lines of the associated DC/AC converter.

7 . The circuit arrangement as claimed in claim 4 , wherein in each further short-circuit path a current-limiting component is connected in series with the respective short-circuit switch.

8 . The circuit arrangement as claimed in claim 7 , wherein the current-limiting component in at least one of the further short-circuit paths is a discharge resistor for input-side intermediate circuit capacitors of the DC/AC converters.

9 . The circuit arrangement as claimed in claim 7 , wherein the current-limiting component in at least one of the further short-circuit paths is an inductor.

10 . The circuit arrangement as claimed in claim 1 , wherein the at least one further short-circuit path or one of the further short-circuit paths runs in parallel with the at least one short-circuit path between the bus lines upstream of all the disconnectors, wherein the short-circuit switch in the at least one further short-circuit path is also connected in series with a fuse.

11 . The circuit arrangement as claimed in claim 10 , wherein the short-circuit switch in the at least one short-circuit path between the bus lines is furthermore connected in series with a current-limiting component, and wherein the short-circuit switch in the at least one further short-circuit path is also connected in series with a current-limiting component.

12 . The circuit arrangement as claimed in claim 1 , wherein each disconnector causes all-pole disconnection of the associated DC/AC converter from the bus lines.

13 . The circuit arrangement as claimed in claim 1 , wherein all DC/AC converters are configured to be connected on their output side via a common AC contactor or a dedicated AC contactor to an output terminal configured to couple to an AC grid.

14 . A use of a circuit arrangement for a photovoltaic inverter, comprising:
two bus lines; input terminals for connecting at least one photovoltaic generator to the bus lines, respectively; at least one DC/AC converter connected to the bus lines; a disconnector between each DC/AC converter and the bus lines, respectively; at least one short-circuit path for short-circuiting a voltage between the bus lines, wherein a short-circuit switch is arranged in the short-circuit path, wherein the at least one short-circuit path runs between the bus lines upstream of all disconnectors between the input terminals and the disconnectors, and wherein the short-circuit switch in the at least one short-circuit path between the bus lines is connected in series with a fuse; and at least one further short-circuit path for short-circuiting the voltage between the bus lines, wherein a short-circuit switch likewise is arranged in the at least one further short-circuit path, wherein the use comprises opening all the disconnectors in the case of conducting short-circuit switches.

15 . The use as claimed in claim 14 , wherein in the circuit arrangement the at least one further short-circuit path runs between the connection lines of the at least one DC/AC converter, and is connected to the connection lines downstream of the disconnector between the disconnector and the at least one DC/AC converter, wherein in the use all short-circuit switches in all short-circuit paths between the bus lines upstream of all disconnectors are closed only after all short-circuit switches in all short-circuit paths downstream of all disconnectors and between the connection lines of the associated DC/AC converter.

16 . The use as claimed in claim 15 , wherein in the circuit arrangement the at least one further short-circuit path or one of the further short-circuit paths runs in parallel with the at least one short-circuit path between the bus lines upstream of all the disconnectors, wherein the short-circuit switch in the at least one further short-circuit path is also connected in series with a fuse.

17 . The use as claimed in claim 14 , wherein in the circuit arrangement the at least one further short-circuit path runs between the connection lines of the at least one DC/AC converter, and is connected to the connection lines downstream of the disconnector between the disconnector and the at least one DC/AC converter, wherein in each further short-circuit path a current-limiting component is connected in series with the respective short-circuit switch, and wherein the current-limiting component in at least one of the further short-circuit paths is a discharge resistor for input-side intermediate circuit capacitors of the DC/AC converters,
wherein in the use each short-circuit switch connected in series with a discharge resistor in one of the further short-circuit paths is closed before all other short-circuit switches are closed.

18 . The use as claimed in claim 14 , wherein in the circuit arrangement all DC/AC converters are configured to be connected on their output side via a common AC contactor or a dedicated AC contactor to an output terminal configured to couple to an AC grid, wherein in the use the AC contactor(s) is/are turned off before the short-circuit switches are closed.

19 . A use of a circuit arrangement for a photovoltaic inverter, comprising:
two bus lines; input terminals for connecting at least one photovoltaic generator to the bus lines, respectively; at least one DC/AC converter connected to the bus lines; a disconnector between each DC/AC converter and the bus lines, respectively; at least one short-circ

Assignees

• Sma Solar Technology Ag

Inventors

• Falk Andreas
• Lukas Franz

Classifications

• H02S40/32

  comprising DC/AC inverter means associated with the PV module itself, e.g. AC modules · CPC title

• H02H3/023

  by short-circuiting · CPC title

• H02H7/20

  for electronic equipment (for converters H02H7/10; for electric measuring instruments G01R1/36; for DC voltage or current semiconductor regulators G05F1/569; for amplifiers H03F1/52; for electronic switching circuits H03K17/08) · CPC title

• H02S40/00 Primary

  Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00 · CPC title

• H02M7/44

  by static converters · CPC title