On-off control circuit for heater in power distribution cabinet

Abstract

The invention discloses an on-off control circuit for a heater in a power distribution cabinet. The on-off control circuit comprises a heater power supply, a heater, a first air switch, a second air switch, a control power supply, an optical coupler and a relay, wherein the replay comprises a coil and a normally open node, a negative electrode of the control power supply is grounded, a positive electrode of the control power supply is connected with the coil of the relay, the coil of the replay is then grounded through the optical coupler, a control loop is formed, the first end part of the first air switch is connected with the normally open node of the relay, the second end part of the first air switch is connected with a positive element of the heater power supply, a negative electrode of the heater power supply is connected with the first end part of the second air switch, the second end part of the second air switch is connected with the first end part of the heater, the second end part of the heater is connected with the normally open node of the relay, a heater loop is formed, and a single chip microcomputer used for controlling the on-off state of the normally open node of the relay is also connected onto the relay.

Description

technical field [0001] The invention relates to a heater switch control circuit in a power distribution cabinet in the field of power transmission and distribution. Background technique [0002] The safe operation of power equipment protection cabinets, instrument boxes, metering cabinets, switch cabinets, terminal boxes and other power equipment will be threatened if they are operated for a long time in an environment where the temperature is too low, the temperature is too high or the humidity is too high. [0003] At present, heaters are installed in the power distribution cabinets to ensure that the temperature and humidity in the power distribution cabinets remain at normal levels. Most of the heaters in the power distribution cabinet are in the normal conduction state, and the heater power supply circuit is powered by the AC busbar, and the heater small switch is used to switch the circuit conduction. Part of the heater adopts the KS-3-4S series temperature and humidi...

AI Technical Summary

Problems solved by technology

[0005] Due to the use of "bang bang" control, the humidity and temperature in the power distribution cabinet will have large instantaneous fluctuations, which cannot be controlled smoothly, and the temperature adjustment time is also long, which is not conducive to the inside of the power distribution cabinet. Stable operation of equipment

At the same time, the use of Bangbang control cannot record the on-off time of the heater, as well as the temperature and humidity when the heater is turned on or off, which is not conducive to the statistics of the working environment of the substation and the increase in line loss

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