Thick-film magnetic isolation direct current solid-state power controller

Abstract

The invention discloses a thick-film magnetic isolation direct current solid-state power controller which comprises a power MOSFET (metal oxide semiconductor field effect transistor), a detection resistor, a power diode, a TVS (transient voltage suppressor) diode, a current conditioning circuit, a voltage detection circuit, a voltage state judgment circuit, a current state judgment circuit, an immediate trip circuit, an inverse time circuit, a short-circuit detection circuit, a driving circuit, a state synthetic circuit, a trip state latch circuit, a time delay reset circuit, a time sequence matching circuit, a DC / DC (direct current / direct current) isolated power supply, a first isolation circuit, a second isolation circuit, a third isolation circuit, a state feedback interface circuit, a control signal interface circuit and a power-on reset circuit. The circuit structure can optimize the electrical properties of the controller, reduce the volume and the weight, improve the reliability and is widely applied to civil low-voltage direct current power distribution systems, aviation, aerospace, tanks, automobiles, ships and other fields.

Description

technical field [0001] The invention belongs to the technical field of power electronics and electric engineering, and in particular relates to a DC solid-state power control device. Background technique [0002] The solid-state power controller is an intelligent power distribution device composed of semiconductor devices produced with the development of the aircraft power distribution system. It is the core component and the final execution component of the solid-state power distribution system. Accept the control signal of the front-end computer and report its status information; when the load is overloaded, it will trip according to the anti-delay characteristic to protect the line and load equipment; when the load is short-circuited, it will quickly act within tens of microseconds Load cut-off; solid-state power controller has the advantages of no arc, no contact, no noise, fast response, small electromagnetic interference, and easy computer remote control. It can be ...

AI Technical Summary

Problems solved by technology

[0005] Soft-on and soft-off functions are essential for DC solid-state power controllers: there is a large inrush current during the turn-on process of capacitive loads. Depending on the size of the load capacitance, the inrush current can reach 2-6 times, or even more than 10 times, which may cause tripping; the soft-on function can well suppress the inrush current when the DC solid-state power controller is turned on with a capacitive load, thereby improving the capacity of the DC solid-state power controller with a capacitive load; In addition, due to the unavoidable distributed inductance in the power distribution line, when the DC solid-state power controller turns off the load, an induced peak voltage caused by di / dt will be generated at both ends of the power semiconductor switch tube, and the soft-off function can be well Solve this problem; at present, DC solid-state power controllers often use some integrated circuit driver chips to solve the soft-on and soft-off problems. First, the effect is not ideal, and second, the scheme is complicated and inconvenient for overall circuit integration.

[0006] (2) Short-circuit protection of DC solid-state power controllers

[0007] As the most serious failure mode, load short-circuit may cause extremely harmful thermal stress, which may cause damage to the solid-state power controller or tripping of the upper protection device; therefore, the solid-state power controller should be able to quickly detect the short-circuit fault and shut down quickly to ensure power MOSFET is safe and the load connected to the same bus bar does not interrupt the power supply; the current short-circuit protection detection method is mostly to detect the voltage at both ends of the power MOSFET. Complex, and poor anti-interference ability, easy to false protection

[0008] (3) Protection of power semiconductor switching tubes in DC solid-state power controllers

[0009] The power semiconductor switch tube is one of the core devices in the DC solid-state power controller. The safety of the power semiconductor switch tube determines whether the function of the DC solid-state power controller can be realized normally; the power semiconductor switch tube in the DC solid-state power controller Protection technology has always been one of the key technologies of solid-state power controllers; at present, snubber circuits are mostly used for the protection of power semiconductor switching tubes. This only solves some electrical stress during the turn-off process, and does not consider possible occurrences in the system. The influence of the surge voltage and load on the power semiconductor switch tube, and the thermal stress of the power MOSFET during long-term operation and overload and short circuit are not considered.

[0010] (4) Timing issues of voltage and current state output in DC solid-state power controllers

[0012] (5) Power-on reset problem of DC solid-state power controller

[0013] The working process of the DC solid-state power controller is usually to supply power to the bias power supply of the control part first, and then control the on-off by sending commands to the control part; power-on reset means that when the SSPC control part is not powered, if the turn-on command , then supply power to the bias power supply of the SSPC control part at this time, then the SSPC should not be turned on; if the SSPC is to be turned on, a shutdown command must be issued first, and then a turn-on command is issued. The existing solid-state power controller does not have this consideration

[0014] (6) Isolation of the DC solid-state power controller and the interface part of the upper computer

[0015] In order to prevent the strong current circuit from interfering with the weak current control circuit, it is usually necessary to provide electrical isolation when the host computer sends on-off control commands to the solid-state power controller and the DC solid-state power controller feeds back the status to the host computer; currently, more methods are used It uses optocoupler isolation, which has the advantages of small size, fast response, easy to cooperate with logic circuits, and convenient use; however, the problems of optocoupler isolation are high power consumption and intolerance to radiation, which limit its use in the aerospace field. use of the space environment

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