Low-voltage electromagnetic switch energy cycle control system

Abstract

The invention relates to an energy circulation control system for a low-voltage electromagnetic switch. The control system adopts two mutually-separated magnetic circuit structures; under independent closed loop control action, a closed loop feedback idea is used in the whole switch movement process; on the basis, an energy management idea is fused to establish an energy circulation coordination control system; a cyclic utilization channel for the magnetic energy of the electromagnetic system, the heat of a contact system, and the circuit load residual energy is established; units for collecting, transferring and storing energy are designed; an energy management mechanism is adopted; a control policy is formed under the fault conditions of sudden increase or sudden drop of voltages, and the like; rapid transfer of the contact energy is realized; and the breaking capacity of the switch is improved.

Description

technical field [0001] The invention relates to a low-voltage electromagnetic switch energy circulation control system. Background technique [0002] In order to meet the challenges of global energy security, environmental pollution and climate change, the future distribution network is entering the post-carbon period of "Internet + distributed energy". Actively developing energy Internet is one of China's main strategies to deal with the next energy revolution. The introduction of new energy, the intelligent management and rational use of traditional energy, and the energy saving and mutual coordination of electrical equipment are all hot issues in current research. Increasing the proportion of electric energy in terminal energy consumption, utilizing decentralized wind energy, solar energy and other renewable energy sources, and developing distributed power generation systems according to local conditions are important ways to realize the Energy Internet. Due to the rando...

AI Technical Summary

Problems solved by technology

[0005] The randomness of the closing phase angle of the electromagnetic mechanism leads to random changes in the excitation current and iron core speed during the pull-in process. At some phase angles, it will be difficult to close the switch, which will affect the reliability of the switch; while in other Although the switch can be reliably closed under the phase angle, it will cause excessive impact energy of the moving and static iron core, resulting in serious contact bounce and affecting its electrical life.

[0006] (2) The working voltage range is narrow and the ability to resist voltage drops is poor

[0009] (3) There is AC running noise

[0010] The periodic sinusoidal change of the coil voltage of the AC electromagnetic appliance leads to the periodic sinusoidal change of the magnetic flux and suction force in the electromagnetic mechanism. When the suction force is smaller than the reaction force, the iron core will generate vibration and noise; The main measure of vibration and noise in the closed state of the system, but at the same time, the addition of the magnetic ring will bring difficulties to the design and analysis of the electromagnetic system; the existence of the magnetic ring will bring additional loss and additional temperature rise to the coil and core; The magnetic ring is easy to break, which affects the mechanical life

[0011] (4) The temperature rise of the electromagnetic system is relatively high

[0013] (5) Coil operating overvoltage exists

Taking the 630A AC contactor as an example, the DC strong excitation mode is adopted, and the peak value of the starting current of the coil can reach about 150A. Such a large starting current will make the electromagnetic mechanism in an over-excited state, and even cause the magnetic circuit of the electromagnetic mechanism to saturate. Increased suction power

At the same time, the switch tube that controls the pull-in process in the electronic module will bear a huge impact current, and the current stress, cost and reliability of the switch tube will be affected

Moreover, the contactor coil is an inductive load, and the coil current cannot change suddenly. The difference between the pull-in current and the hold-in current of this control method is dozens of times. In the process of changing from high-voltage pull-in to low-voltage hold, the coil current must change The current decays continuously to the holding current. If the power supply mode of the switching power supply is adopted, the large current at the moment of switching is drawn from the secondary side of the switching power supply, which may trigger the overcurrent protection function of the switching power supply or lower the output voltage of the switching power supply, causing the entire The work of the system is unstable, even the system is reset, and it also increases the difficulty of anti-interference of the control circuit

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