US 2018/0006548 A1 · Bypass Switch For High Voltage DC Systems

Abstract

Many DC applications switching converter modules are multilevel, series connected converters. If an individual converter cell fails, it is desirable to be able to bypass the failed cell, in order to continue operating the rest of the converter. A bypass switch is provided as a hybrid switch, including a parallel combination of a slow mechanical switch with high current conduction capability and a low power semiconductor switch with faster acting switching capabilities. When the bypass switch is activated (closed), the low power semiconductor switch is turned on first and quickly establishes the bypass within 10 μs or less, to temporarily conduct required current until the slower mechanical switch turns on. The mechanical switch is subsequently turned on with zero voltage, given the parallel-connected semiconductor switch being on. If desired, the semiconductor switch can then be turned off with zero voltage, given the presence of the mechanical switch. When the bypass switch is deactivated (opened), the semiconductor switch can first be turned on to divert part of the current from the mechanical switch. The mechanical switch can then be turned off at low voltage, since the mechanical switch is shorted by the semiconductor switch. Once the mechanical switch is off, the semiconductor switch can be quickly turned off.

Claims26

Dependent claims

A bypass switch for an associated electrical module which can be engaged or bypassed relative to an electrical device, said switch comprising,

a first switch terminal, for one parallel connection with an associated electrical module;
a second switch terminal, for a second parallel connection with an associated electrical module;
an electronic switch electrically connected in series between said first and second switch terminals;
a mechanical switch electrically connected in series between said first and second switch terminals, and electrically in parallel with said electronic switch;
and
a control mechanism for selective actuation of each of said electronic switch and said mechanical switch, to selectively control electrical bypass and engagement of an associated electrical module connected in series between said first and second switch terminals electrically in parallel with said bypass switch.

3 more elements

Methodology for operation of a bypass switch for an associated electrical module which can be engaged or bypassed relative to an electrical device, said methodology comprising,

providing an electronic switch electrically connected in series between respective first and second switch terminals;
providing a mechanical switch electrically connected in series between said first and second switch terminals, and electrically in parallel with said electronic switch;
associating an electrical module electrically connected in parallel with said electronic switch and said mechanical switch;
and
selectively actuating each of said electronic switch and said mechanical switch, to selectively control electrical bypass and engagement of said associated electrical module.

2 more elements

A method for operation of a multilevel DC switching converter comprising plural series-connected individual converter cells in the event of an individual converter cell failure, comprising:

providing a hybrid bypass switch associated in parallel for each respective individual converter cell of the multilevel converter;
operating each respective hybrid bypass switch to be closed so as to bypass its respective associated individual converter cell in the event of failure of such cell, in order to continue operating the rest of the converter;
and
operating each respective hybrid bypass switch to be opened so as to not bypass its respective associated individual converter cell during normal operation of such cell;
wherein each respective hybrid bypass switch comprises an electronic switch electrically connected in series between respective first and second switch terminals which are in parallel with the associated individual converter cell of the hybrid bypass switch, and comprises a mechanical switch electrically connected in series between the first and second switch terminals of such hybrid bypass switch, and electrically in parallel with the electronic switch of such hybrid bypass switch.

2 more elements

Dependencies are inferred from the claim text.

Bypass Switch For High Voltage DC Systems

Life of this patent

Bypass Switch For High Voltage DC Systems

Life of this patent

Abstract

Claims26