Power frequency transformer surge current suppression circuit, power frequency transformer and its intrinsically safe power supply

Abstract

The invention provides an industrial frequency transformer impact current suppression circuit. The industrial frequency transformer impact current suppression circuit comprises an energy taking unit arranged on a fire wire of a transformer, a rectification unit electrically connected with the output end of the energy taking unit, a constant voltage unit electrically connected with the rectification unit and a current suppression unit electrically connected with the output end of the constant voltage unit, and the current suppression unit is arranged on the fire wire of the transformer and electrically connected with a fuse F1 of the transformer. Most input voltages can be loaded on a current limiting resistor in the power-on process, all the voltages loaded on the current limiting resistor are loaded at the two input ends of the transformer after the power-on process, therefore, large impact currents cannot be generated by the transformer at the starting-up moment, meanwhile, potential differences are prevented from being generated on the current limiting resistor, the fuse can be effectively prevented from being burnt out by the impacts of the large currents, and the fault rate of the fuse of the industrial frequency transformer is lowered. In addition, high cost caused by transformer power increase through the mode of increasing rated currents of the fuse can be avoided.

Description

technical field [0001] The invention relates to the field of power transformation equipment, in particular to a power frequency transformer surge current suppression circuit, a power frequency transformer and an intrinsically safe power supply thereof. Background technique [0002] Most of the intrinsically safe power supplies use power frequency transformers as the main components for step-down and isolation. The power frequency transformers used for intrinsically safe power supplies need to undergo transformer type tests to adjust the input voltage to the rated voltage of the transformer. The load of the winding adjusts the input current to 1.7In (In is the rated current value of the matching fuse), and the test lasts for 6 hours. The temperature of the winding of the transformer does not exceed 150°C. Due to the inductive components in the transformer room, in the actual use process, it will pass through the form The fuse of the tested transformer is easily damaged by the...

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Problems solved by technology

[0002] Most of the intrinsically safe power supplies use power frequency transformers as the main components for step-down and isolation. The power frequency transformers used for intrinsically safe power supplies need to undergo transformer type tests to adjust the input voltage to the rated voltage of the transformer. The load of the winding adjusts the input current to 1.7In (In is the rated current value of the supporting fuse), and the test lasts for 6 hours. The temperature of the winding of the transformer does not exceed 150 ° C. Due to the inductive components in the transformer room, in the actual use process, through the form The fuse of the tested transformer is easily damaged by the instantaneous high current at the moment of starting up, causing a fault and affecting production and life. If a fuse with a higher rated current value is selected, the power of the transformer needs to be increased, thereby making the overall intrinsically safe power supply high cost,

[0003] In view of this, it is necessary to propose a device that can suppress the instantaneous large current generated when the transformer is turned on, so as to prevent the fuse of the transformer from being burned by the instantaneous high current, thereby reducing the failure rate of the intrinsically safe power supply, and avoiding the loss of the power of the transformer high cost

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