In industrial applications, the secondary current from high-voltage three-phase transmission line current transformers can be converted into millivolt voltage output through three Hall electrical current sensors in proportion, and then amplified and filtered with an active filter, to obtain the required voltage signal, which can be sent to a computer for measurement or processing. The use of Hall current sensors here can conveniently realize distortion-free and delay-free signal conversion.
In the DC automatic control speed regulation system, Hall current-voltage sensors can directly replace current transformers, not only with good dynamic response, but also with the best control of rotor current and overload protection of thyristors.
In this application, Hall electrical current sensors are used for control to ensure the normal operation of the inverter power supply. Hall current sensor 1 sends out a signal and performs feedback to control the trigger angle of the thyristor. Hall current sensor 2 sends out a signal to control the inverter, and Hall current sensor 3 controls the float charge power supply. Because of its fast response speed, Hall current sensors are particularly suitable for uninterrupted power supplies in computers.
In the power supply of electronic spot welder, Hall electrical current sensors play a role in measurement and control. Its fast response can reproduce current and voltage waveforms, which can be fed back to controllable rectifiers A and B to control their output. Adding an AC wave to the DC by using a chopper can more accurately control the current. Detecting the current with Hall current sensors can not only measure the true instantaneous value of the current, but also avoid introducing losses.
AC variable frequency speed control motor has been widely used in developed countries all over the world, and has a trend to replace DC speed regulation. Controlling the motor with a frequency converter can save more than 10% of energy. In the frequency converter, the main function of Hall current sensors is to protect expensive high-power transistors. Because the response time of Hall current sensors is often less than 5μs, when overload or short circuit occurs, the power can be cut off before the transistor reaches the limit temperature, so as to ensure reliable protection of the transistor.
Hall current sensors can be installed on distribution lines for load management. The output of Hall current transducer is connected to a computer to monitor power consumption. If overload is detected, the controlled line will be disconnected in time to ensure the safety of electrical equipment. With this device, load allocation, remote control, remote measurement, inspection and other operations can also be carried out.
Automatic compensation of reactive power in power system means that the compensation capacity changes with the load and voltage fluctuations, and the capacitors are timely and accurately put into and cut off to avoid unreasonable and uneconomical overcompensation and under-compensation during the compensation process, so that the power factor of the power grid always remains optimal. If Hall current and voltage sensors are used for automatic sampling of reactive power, they will have significant advantages in ensuring "timely and accurate" due to their fast response speed and no phase difference.