Wireless sensing device

A sensing system, comprising a sensing device for monitoring an electrical component or apparatus, and a flexible strap, the sensing device being attachable to an electrical conductor and comprising:

• a sensor for measuring at least one physical property;
• a wireless communication unit for transmitting measurement data to a receiver;
• an energy harvesting unit configured to harvest energy from a current flowing through the electrical conductor and comprising an electromagnetic coil wound around a core;
• and
• a connection mechanism to make the core connectable to the flexible strap, the flexible strap comprising a material having a high magnetic permeability,
• wherein the connection mechanism comprises a recess provided in the core for inserting an end of the flexible strap, and wherein a part of the flexible strap to be inserted into the recess has a larger volume than the recess,
• the sensing device being configured to be operable when no flexible strap is connected to the core and energy is harvested via an open magnetic circuit, as well as when the flexible strap is connected to the core and energy is harvested via a closed magnetic circuit.

A switchgear apparatus, comprising a sensing device for monitoring an electrical component or apparatus, the sensing device being attachable to an electrical conductor and comprising:

• a sensor for measuring at least one physical property;
• a wireless communication unit for transmitting measurement data to a receiver;
• an energy harvesting unit configured to harvest energy from a current flowing through the electrical conductor and comprising an electromagnetic coil wound around a core;
• and
• a connection mechanism to make the core connectable to a flexible strap, the flexible strap comprising a material having a high magnetic permeability,
• wherein the connection mechanism comprises a recess provided in the core for inserting an end of the flexible strap, and wherein a part of the flexible strap to be inserted into the recess has a larger volume than the recess,
• the sensing device being configured to be operable when no flexible strap is connected to the core and energy is harvested via an open magnetic circuit, as well as when the flexible strap is connected to the core and energy is harvested via a closed magnetic circuit.

A method of monitoring an electrical component or apparatus, the method comprising:

• attaching a sensing device to an electrical conductor of the electrical component or apparatus, the sensing device comprising:
• a sensor for measuring at least one physical property;
• a wireless communication unit for transmitting measurement data to a receiver;
• an energy harvesting unit configured to harvest energy from a current flowing through the electrical conductor and comprising an electromagnetic coil wound around a core;
• and
• a connection mechanism to make the core connectable to a flexible strap, the flexible strap comprising a material having a high magnetic permeability,
• wherein the connection mechanism comprises a recess provided in the core for inserting an end of the flexible strap, and wherein a part of the flexible strap to be inserted into the recess has a larger volume than the recess,
• the sensing device being configured to be operable when no flexible strap is connected to the core and energy is harvested via an open magnetic circuit, as well as when the flexible strap is connected to the core and energy is harvested via a closed magnetic circuit.