Classification of Common Electrical Current Sensors

Current transducer is a kind of detection device that can sense the information of the measured current, and transform the detected information into the required electric signals or other forms of information output according to certain rules, so as to meet the requirements of information transmission, processing, storage, display, recording, and control. With the development of technology, current sensors are also constantly innovating and developing. Let's make a comparison of the current sensors commonly seen nowadays.

Electrical current sensors, also known as magnetic sensors, can be used in household appliances, smart grids, electric vehicles, wind power generation, etc. Many magnetic sensors are used in our lives, such as computer hard drives, compasses, and household appliances. It is a kind of detection device that can sense the information of the measured current, and transform the detected information into the required electric signals or other forms of information output according to certain rules, so as to meet the requirements of information transmission, processing, storage, display, recording, and control. They can mainly be divided into: shunt, electromagnetic current transformer, and electronic current transformer.

Resistor shunt for current sensing

This is used to measure direct current, which is made based on the principle that voltage is generated at both ends of the resistor when direct current flows through the resistor. The advantage of the resistance shunt is high accuracy, fast response speed, and low cost; but the disadvantage is that there is no electrical isolation between the measurement circuit and the measured current. The resistance shunt is suitable for measuring low-frequency small-amplitude current.

Hall effect current transducer

This is made according to the Hall effect principle and the application of Ampere's law, that is, a magnetic field proportional to the current is generated around the current-carrying conductor, and the Hall device is used to measure this magnetic field. Therefore, non-contact measurement of current is possible. Hall effect current sensors can measure direct current and alternating current, with a frequency of up to 100KHz, high accuracy, and good isolation.

Flux-gate current transducer

This utilizes the non-linear relationship between the magnetic induction intensity and the magnetic field strength in the saturated excitation of the high permeability magnetic core in the measured magnetic field to measure the weak magnetic field. This physical phenomenon is like a "gate" for the measured magnetic field. Through this "gate", the corresponding magnetic flux is modulated, and an induced electromotive force is generated. The magnetic field generated by the current is measured indirectly by utilizing this phenomenon.

Electronic current transformers include Hall effect current sensors, Rogowski coil current sensors, and frequency conversion power sensors (which can be used for voltage, current, and power measurement) dedicated to frequency conversion power measurement. Compared with electromagnetic current transformers, electronic current transformers do not have magnetic saturation, have a wider transmission bandwidth, smaller secondary load capacity, smaller size, lighter weight, and are the development direction of current sensors in the future.