Power factor measurement device

A power factor measurement apparatus that measures a power factor of power consumed at a load connected to a power source via a connection line, the apparatus comprising:

• a power factor sensor connected with the load in parallel, the power factor sensor being supplied with a current from the power source connected with the load, the power factor sensor comprising first and second magnetic elements, resistance changes of the first and second magnetic elements due to an identical external magnetic field being different from each other;
• a voltage detector configured to detect a differential voltage between the first and second magnetic elements;
• and
• a power factor calculator that calculates the power factor based on the differential voltage, wherein
• the first magnetic element comprises:
• a strip-shaped first magnetic film;
• a first pair of element terminals at both ends of the first magnetic film;
• and
• a first bias module that applies a magnetic field parallel to a face of the first magnetic film, there being a first angle between a direction of the first magnetic field and a direction of a current flowing between the first pair of element terminals, and the second magnetic element comprises:
• a strip-shaped second magnetic film;
• a second pair of element terminals at both ends of the second magnetic film;
• and
• a second bias module that applies a magnetic field parallel to a face of the second magnetic film, there being a second angle between a direction of the second magnetic field and a direction of a current flowing between the second pair of element terminals, and
• the first angle is different from the second angle.

A power factor measurement apparatus that measures a power factor of power consumed at a load connected to a power source via a connection line, the apparatus comprising:

• a power factor sensor connected with the load in parallel, the power factor sensor being supplied with a current from the power source connected with the load, the power factor sensor comprising first and second magnetic elements, resistance changes of the first and second magnetic elements due to an identical external magnetic field being different from each other;
• a voltage detector configured to detect a differential voltage between the first and second magnetic elements;
• and
• a power factor calculator that calculates the power factor based on the differential voltage, wherein
• the first magnetic element comprises:
• a strip-shaped first magnetic film;
• a first pair of element terminals at both ends of the first magnetic film;
• and
• a first plurality of conductors on a face of the first magnetic film, there being a first angle between a direction between the first pair of element terminals and a direction of the first plurality of conductors, and
• the second magnetic element comprises:
• a strip-shaped second magnetic film;
• a second pair of element terminals at both ends of the second magnetic film;
• and
• a second plurality of conductors on a face of the second magnetic film, there being a second angle between a direction between the second pair of element terminals and a direction of the second plurality of conductors, and
• the first angle is different from the second angle.

A power factor measurement apparatus that measures a power factor of power consumed at a load connected to a power source via a connection line, the apparatus comprising:

• a power factor sensor connected with the load in parallel, the power factor sensor being supplied with a current from the power source connected with the load, the power factor sensor comprising first and second magnetic elements, resistance changes of the first and second magnetic elements due to an identical external magnetic field being different from each other;
• a voltage detector configured to detect a differential voltage between the first and second magnetic elements;
• and
• a power factor calculator that calculates the power factor based on the differential voltage,
• wherein an angle between a magnetization facilitating axis of the first magnetic element and a direction of a current flowing in the first magnetic elements is different from an angle between a magnetization facilitating axis of the second magnetic element and a direction of a current flowing in the second magnetic element.

A power factor measurement method to measure a power factor of power consumed at a load connected to a power source via a connection line, the method comprising:

• detecting a differential voltage between first and second magnetic elements of a power factor sensor connected with the load in parallel, the power factor sensor being supplied with a current from the power source connected with the load, resistance changes of the first and second magnetic elements due to an identical external magnetic field being different from each other;
• and
• calculating the power factor based on the differential voltage,
• wherein calculating the power factor comprises:
• retrieving a low frequency component from the differential voltage;
• retrieving a high frequency component from the differential voltage;
• rectifying the high frequency component;
• and
• dividing the low frequency component by the rectified high frequency component.