A Breakdown Automatic Protection Device for Insulation Aging Test

Abstract

The invention discloses an automatic breakdown protection device for insulation aging test. A lens module is electrically connected to an FIFO chip. The FIFO chip, a display screen and a driving module are electrically connected to corresponding I / O ports of a microcontroller. A power supply is electrically connected to the microcontroller and the power supply end of the driving module. A current-limiting resistor and a high-voltage solid-state switch are sequentially connected in series between a pulse power supply and a test electrode. The driving module is electrically connected to the driving end of the high-voltage solid-state switch through a shielding wire. The test electrode is in contact with an insulating material sample. The pulse power supply, the current-limiting resistor, thehigh-voltage solid-state switch, the test electrode and the insulating material sample are all placed in a shielding case. Visible light serves as a sensing physical quantity, and a plurality of insulating material samples can be tested and protected at the same time. The problems that in the prior art, the risk of strong electromagnetic interference is high, the cost is high, and false triggering and false operation are likely to happen are solved.

Description

technical field [0001] The invention belongs to the technical field of high voltage and insulation, and in particular relates to a breakdown automatic protection device. Background technique [0002] With the increasing introduction of new uncertain loads (such as electric vehicles) and distributed renewable energy, the transmission and distribution system has gradually increased the requirements for the two-way flow of energy between AC and DC and optimal management. In this context, energy routers are proposed as key devices that can realize the multi-directional flow of energy and the active control of power flow. Among them, the power electronic transformer (also known as solid-state transformer) is the core component of the energy router. It combines the power electronic conversion circuit with the high-frequency transformer. It not only has the functions of voltage transformation, isolation and energy transmission, but also can control the voltage phase , frequency an...

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Problems solved by technology

Although this study provides a protection device for shutting down the nanosecond pulse power supply, there are still the following problems: (1) The repetitive frequency high-voltage nanosecond pulse source has strong electromagnetic radiation, especially for the current acquisition link. , so that the breakdown protection device is prone to mistriggering or misoperation; (2) Due to the randomness of the discharge and the changeable test conditions, the trigger level of the oscilloscope needs to be artificially set several times according to different test situations, which will also lead to the failure of the protection action. False triggering or malfunction; (3) The shutdown signal of the device is used to directly control the power off, and it is not suitable for a single power supply to conduct insulation aging tests on multiple samples at the same time; (4) The protection device relies on digital with trigger reliable output Oscilloscope, expensive

Although the tester is a protection device based on temperature sensing, there are still the following problems: (1) Temperature sensing depends on the degree of close contact between the thermistor and the current limiting resistor, but if there is a slight gap, the temperature measurement results will be different (2) Since the temperature sensing is realized by using a thermistor detection resistor and a detection bridge, and the thermistor detection resistor is in close contact with the current limiting resistor, it indicates that the bridge circuit must be physically close to the aging test circuit Connected, thus exposed to the strong electromagnetic radiation environment generated by high-frequency high-voltage pulses, it is inevitable to be subject to strong electromagnetic interference, which is likely to cause misjudgment and misoperation; (3) Since the temperature on the current-limiting resistor before and after insulation breakdown is It rises slowly and depends on the rated power of the current-limiting resistor, making the response time of temperature sensing as long as several seconds or even minutes (equivalent to tens of thousands of pulse voltage cycles), and it is impossible to cut off the insulation breakdown branch in time. Insulation sample testing in branch circuits can have a large impact

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