Hybrid circuit breaker with improved current capacity per device size

A method for operating a hybrid circuit breaker, the hybrid circuit breaker comprising:

• input connectors configured to receive electrical energy from a power grid;
• output connectors configured to transfer electrical energy to a load;
• current paths each connecting a respective input connector, of the input connectors, and a respective output connector, of the output connectors;
• an electro-mechanical bypass switch in at least one of the current paths;
• a semiconductor circuit in parallel with the electro-mechanical bypass switch;
• a controller configured to control a commutation from the at least one current path, in which the electro-mechanical bypass switch is arranged, to the semiconductor circuit in case of a switching operation;
• and
• an active cooling device arranged in a direct vicinity of the electro-mechanical bypass switch, the method comprising:
• operating the active cooling device to actively cool movable parts of the electro-mechanical bypass switch,
• wherein the hybrid circuit breaker is configured to satisfy:
• A<n·0.25·Icu/di
• wherein A is an active chip area of the semiconductor circuit in cm2, n is a number of power switching elements in the semiconductor circuit, Icu is a short circuit current switching capacity of the hybrid circuit breaker in Ampere, and di is a current density of a single power switching element in A/cm2.

A hybrid circuit breaker, the hybrid circuit breaker comprising:

• input connectors configured to receive electrical energy from a power grid;
• output connectors configured to transfer electrical energy to a load;
• current paths, each connecting a respective input connector, of the input connectors, and a respective output connector, of the output connectors;
• an electro-mechanical bypass switch in at least one of the current paths;
• a semiconductor circuit in parallel with the electro-mechanical bypass switch;
• a controller configured to control a commutation from the at least one current path in which the electro-mechanical bypass switch is arranged to the semiconductor circuit in a switching operation;
• and
• an active cooling device in a direct vicinity of the electro-mechanical bypass switch, the active cooling device being adapted to cool movable parts of the electro-mechanical bypass switch,
• wherein the active cooling device comprises a fan placed in a direct vicinity of a fixed switching contact and a movable switching contact of the electro-mechanical bypass switch,
• wherein the active cooling device is arranged such that a distance between the fan and the movable switching contact of the electro-mechanical bypass switch is less than 20 mm and is configured to guide an air stream of the fan directly over the movable switching contact, and
• wherein the active cooling device includes a housing and the electro-mechanical bypass switch includes a base body, and wherein the housing is attached to the base body such that the housing and base body together direct the air stream of the active cooling device over the movable switching part.