Energy Storage System with Common-Mode Arcing Detection Function, and Photovoltaic Energy Storage Device

A battery cluster comprising:

• one or more battery systems coupled in series and comprising:
• a first positive output end;
• and
• a first negative output end;
• a common-mode current detection circuit configured to detect a common-mode current in a connected circuit, wherein the common-mode current detection circuit comprises:
• a first end coupled to the first positive output end;
• and
• a second end coupled to the first negative output end;
• and
• a controller configured to control the battery cluster to not output electric energy outside the battery cluster when a first frequency domain component of the common-mode current is greater than a first preset amplitude.

An energy storage system comprising:

• a battery cluster comprising:
• one or more battery systems coupled in series and comprising:
• a positive output end;
• and
• a negative output end;
• a common-mode current detection circuit configured to detect a common-mode current in a connected circuit, wherein the common-mode current detection circuit comprises:
• a first end coupled to the positive output end;
• and
• a second end coupled to the negative output end;
• and
• a controller configured to control the battery cluster to not output electric energy outside the battery cluster when a first frequency domain component of the common-mode current is greater than a first preset amplitude;
• and
• a power conversion circuit electrically coupled to the battery cluster and configured to:
• convert a first direct current of the battery cluster into a first alternating current and output the first alternating current;
• or
• convert an input alternating current into a second direct current and output the second direct current to the battery cluster.

A photovoltaic energy storage device comprising:

• a photovoltaic power generation apparatus configured to generate a first direct current;
• an energy storage system comprising:
• a battery cluster comprising:
• one or more battery systems coupled in series and comprising:
• a positive output end;
• and
• a negative output end;
• a common-mode current detection circuit configured to detect a common-mode current in a connected circuit, wherein the common-mode detection circuit comprises:
• a first end coupled to the positive output end;
• and
• a second end coupled to the negative output end;
• and
• a controller configured to control the battery cluster to not output electric energy outside the battery cluster when a frequency domain component of the common-mode current is greater than a first preset amplitude;
• and
• a power conversion circuit electrically coupled to the battery cluster and configured to:
• convert a second direct current of the battery cluster into a first alternating current and output the first alternating current;
• or
• convert an input alternating current into a third direct current and output the third direct current to the battery cluster;
• and
• an inverter coupled to the photovoltaic power generation apparatus and the energy storage system and configured to:
• convert the first direct current into the input alternating current;
• and
• transmit the input alternating current to the energy storage system.