Three-phase AC 230V power supply health detection circuit applied to airborne product

Abstract

The invention belongs to the technical field of aviation electrical, and particularly relates to a three-phase AC 230V power supply health detection circuit applied to airborne products. Comprising three step-down circuits with isolation transformers, three rectification filter circuits, three hysteresis comparator circuits, an output buffer circuit and a CPU processor, and the three step-down circuits with the isolation transformers receive line voltages of three-phase alternating current respectively; the output end of the step-down circuit with the isolation transformer is connected with the input end of the corresponding rectification filter circuit, and the output end of the rectification filter circuit is connected with the in-phase input end of the corresponding hysteresis comparator circuit; the inverted input end of the hysteresis comparator circuit is connected with threshold reference voltage; the output end of the hysteresis comparator circuit is connected with the input end of the output buffer circuit, and output data of the output buffer circuit and a control command are simultaneously input to the CPU processor. And the isolation effect is low in time delay.

Description

Technical Field

[0001] The invention belongs to the field of aviation electrical technology, and in particular relates to a three-phase AC230V power supply health detection circuit applied to airborne products. Background Art

[0002] With the development trend of large aircraft and more electric aircraft, there are more and more AC230V AC systems on aircraft. The health detection of three-phase AC power supply of airborne products is one of the necessary functions of the product. There are two main traditional detection forms. The first traditional method is to collect specific voltage values ​​through sampling resistors, effective value chips, etc. This method has a complex circuit structure, high cost, large collection delay, no isolation effect, and poor anti-interference ability. The second traditional method is to collect through optocouplers and rectifier bridges. This method cannot accurately set the detection threshold and the collection delay is more than 100ms. Summary of the invention

[0003] Purpose of the invention: To provide a three-phase AC230V power supply health detection circuit for airborne products to solve the problems of poor isolation and high delay.

[0004] Technical solution:

[0005] A three-phase AC 230V power supply health detection circuit applied to airborne products comprises: three-way step-down circuits with isolation transformers, three-way rectifier filter circuits, three-way hysteresis comparator circuits, an output buffer circuit, and a CPU processor, wherein the three-way step-down circuits with isolation transformers respectively receive the line voltage of the three-phase AC power; the output end of the step-down circuit with isolation transformer is connected to the input end of the corresponding rectifier filter circuit, and the output end of the rectifier filter circuit is connected to the in-phase input end of the corresponding hysteresis comparator circuit; the inverting input end of the hysteresis comparator circuit is connected to a threshold reference voltage; the output end of the hysteresis comparator circuit is connected to the input end of the output buffer circuit, and the output data and control commands of the output buffer circuit are simultaneously input to the CPU processor.

[0006] Furthermore, the three step-down circuits with isolation transformers are the same. The first step-down circuit with isolation transformer includes: resistor RB1, resistor RB2, resistor R5, and transformer T1, wherein one end of the primary side of transformer T1 is connected to one end of resistor RB2 and one end of resistor R5; the other end of resistor RB2 is connected to one end of resistor RB1; the other end of resistor RB1 is connected to the A-phase input end of three-phase alternating current; the other end of resistor R5 and the other end of the primary side of transformer T1 are connected to the B-phase input end of three-phase alternating current.

[0007] Furthermore, the three-way rectifier and filter circuits have the same structure. The first rectifier and filter circuit includes: a diode D1, a capacitor C1, a resistor RB3, and a capacitor C2, wherein one end of the secondary side of the transformer T1 is connected to the anode of the diode D1; the cathode of the diode D1 is connected to one end of the capacitor C1, one end of the resistor RB3, and one end of the capacitor C2; the other end of the capacitor C1, the other end of the resistor RB3, the other end of the capacitor C2, and the other end of the secondary side of the transformer T1 are grounded.

[0008] Furthermore, the three hysteresis comparator circuits have the same structure. The first hysteresis comparator circuit includes: a resistor R4, a resistor R6, a resistor R3, and a comparator IC1B, wherein the non-inverting input terminal of the comparator IC1B is connected to one end of the resistor R4 and one end of the resistor R6, and the other end of the resistor R4 is connected to the cathode of the diode D1; the reverse input terminal of the comparator IC1B is connected to the output terminal of the bridge voltage divider circuit; the output terminal of the comparator IC1B is connected to the other end of the resistor R6 and one end of the resistor R3; and the other end of the resistor R3 is connected to the DC power supply VCC.

[0009] Furthermore, the bridge voltage divider circuit includes a resistor R1 and a resistor R2, wherein one end of the resistor R1 is connected to one end of the resistor R2, the other end of the resistor R1 is connected to a DC power supply VCC, and the other end of the resistor R2 is grounded.

[0010] Furthermore, the transformer has a turns ratio of 1:1, and the three-phase AC power and signal isolation is achieved through the transformer to improve the product's anti-interference ability.

[0011] Furthermore, by adjusting the parameters of the rectifier and filter circuit, the acquisition delay of the three-phase AC230V power supply health detection circuit is reduced to less than 100us.

[0012] Furthermore, the phase voltage collection interval is set by adjusting the hysteresis comparator circuit parameters.

[0013] Beneficial effects:

[0014] Aiming at the shortcomings of AC230V three-phase power supply health detection of traditional aircraft, a method for AC230V three-phase power supply health detection applied to airborne products is provided. The present invention includes: a two-line voltage acquisition form of three-phase AC power supply, realizing 2-line voltage determination of three-phase AC power supply health status detection, small circuit scale, transformer isolation, strong anti-interference ability, shorter acquisition delay of rectifier filter circuit below 100us, hysteresis comparator circuit can accurately set the threshold interval, reduce the occurrence of false acquisition, higher stability, data buffer circuit, CPU bus control circuit can realize discrete quantity to digital quantity conversion, convenient CPU recognition, higher readability and operability. The whole system detection method, circuit design, calculation process, and control logic method of the present invention meet the forward design requirements of aviation airborne products. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the principle block diagram of AC230V three-phase AC power supply health detection.

[0016] Figure 2 This is the AC230V three-phase AC power health detection circuit diagram. DETAILED DESCRIPTION

[0017] In order to solve the above technical problems, the present invention provides a three-phase AC230V power supply health detection circuit for airborne products, such as Figure 1 , AC230V three-phase AC power health detection principle block diagram, including three-way step-down circuit with isolation transformer, three-way rectifier filter circuit, three-way hysteresis comparator circuit, output buffer circuit, CPU processor.

[0018] The present invention collects the health status of three-phase three-phase AC 400V line voltages, and detects the health status of three-phase AC 230V input phase voltage by combining two phases separately, which greatly reduces the failure rate of the system and improves the reliability of the overall AC voltage detection system. The entire system can complete the health detection of AC230V three-phase power supply within 100us. Specifically, it includes three-way step-down circuits with isolation transformers, rectifier filter circuits, hysteresis comparator circuits, output buffer circuits, and CPU bus control circuits. The method is characterized by realizing the health detection of three-phase power supply by combining line voltage collection in pairs, with good transformer isolation and isolation effect, low delay, accurate setting of threshold value, strong readability, and small circuit scale. In addition, the present invention has high acquisition accuracy, fast detection rate, strong anti-interference ability, high reliability, and typical promotion value.

[0019] The three-way step-down circuit with isolation transformer is mainly used to collect AC230V three-phase line voltage. The advantage of collecting line voltage is that any two ways can realize the detection of three-phase AC voltage. The circuit scale is simple. When any one way fails, the three-phase voltage detection can also be completed. The circuit scale is small and the reliability is high. The principle is that the front-stage voltage divider resistor steps down the input to the primary side of the 1:1 transformer, and the transformer output is 1 / 201 line voltage input. At the same time, it also completes the isolation of three-phase AC power electricity and signal electricity to enhance the product's anti-interference ability.

[0020] The rectifier and filter circuit uses the unidirectional conduction characteristics of the diode to complete the half-wave rectification of AC to DC. The stable collection voltage after RC filtering is output to the hysteresis comparator circuit, and the collection delay is less than 100us.

[0021] Hysteresis comparator circuit, the threshold voltage collected is set at the reverse input end of the comparator, and the phase voltage range is limited to 190V-210V, that is, the line voltage range is 329V-364V, that is, when the collected three-phase power supply voltage rises above 210V, it is considered that the collected AC230V voltage is considered that the three-phase power supply is in a healthy state at this moment; when the voltage drops to 190V, it is considered that the AC230V voltage is not collected, and the three-phase power supply is considered to be in an unhealthy state at this moment. The threshold value can be set accurately, and the hysteresis characteristic is set relative to the single threshold value to avoid false collection and increase the stability and reliability of system detection.

[0022] The output data buffer is used for data buffer output for use by the CPU power-on BIT and cycle BIT, directly converting discrete quantity signals into digital quantity signals for direct recognition by the CPU.

[0023] The CPU processor determines the status of the AC230V source health detection through the data bus D0-D2 value. If a high level 1 is collected, it is considered that AC230V is detected, and if a low level 0 is collected, it is considered that AC230V is not detected.

[0024] In order to make the purpose, content, and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 2 , a three-phase AC power health detection circuit diagram, the circuit of the present invention includes three-way step-down circuits with isolation transformers, three-way rectifier filter circuits, three-way hysteresis comparator circuits, an output buffer circuit, and a CPU processor.

[0026] Working principle: Three-way step-down circuit with isolation transformer, the primary side of the transformer uses three resistors to divide the voltage so that the AC400V left and right line voltage is reduced to 400V*R5 / (RB1+RB2+R5). The three-way voltage divider circuit components are resistor RB1, resistor RB2, resistor R5, resistor RB4, resistor RB5, resistor R9, resistor RB7, resistor RB8, and resistor R13. The two-line voltage detection combination can determine the voltage state of the three-phase electricity. The circuit scale is simple. The voltage collected by the voltage divider resistor is transmitted to the secondary side of the transformer through transformer isolation, and then output to the rectifier and filter circuit. The transformer electromagnetic induction principle is used to realize the electrical isolation of the three-phase AC power input signal and the secondary transformer signal. The transformer ratio is 1:1; the rectifier and filter circuit uses the unidirectional conductivity of the diode to complete the half-wave rectification of the AC power. The diode D1, the anode is connected to the transformer Pin. 3. The cathode of the diode is connected to the same potential end of capacitor C1, capacitor C2, pull-down discharge resistor RB3 and current limiting resistor R4, and the stable voltage after RC filtering is output to the positive input end of the hysteresis comparator circuit. The collection delay is less than 100us. The principles of the second and third paths are the same as the first path. The second and third devices include diode D2, capacitor C3, resistor RB6, capacitor C4, resistor R8, diode D3, capacitor C6, resistor RB9, capacitor C7, and resistor R12; the threshold voltage collected is set at the reverse input terminal of the IC1B comparator in the hysteresis comparator circuit, and the phase voltage hysteresis interval is set to 190V-210V, that is, the line voltage interval is 329V-364V. When the level of the comparator's positive input terminal exceeds the corresponding level of the limited interval, that is, the collected phase voltage rises by more than 210V, it is considered that the AC230V voltage is collected and the three-phase power supply is in a healthy state at this moment. When the voltage drops to 190V, it is considered that the AC230V voltage is not collected, and it is considered that the three-phase power supply is in an unhealthy state at this moment. The threshold value can be set accurately, and the resistors R1 and R2 are divided by a 15V bridge. Resistor R6 is the comparator feedback resistor used to adjust the hysteresis interval, resistor R3 is the output pull-up resistor, the second and third hysteresis comparator circuits are consistent with the first principle, and the components are resistor R10, comparator IC1A, resistor R7, resistor R14, comparator IC3A, and resistor R11 respectively; the output data buffer circuit is used for data buffer output for CPU power-on BIT and cycle BIT, and directly converts discrete quantity signals into digital quantities for direct identification by the CPU. A0, A1, and A2 correspond to the acquisition of 3 voltage acquisition discrete quantity signals. When the buffer OE end is pulled low and output to the CPU data line D0-D2 end, the CPU reads the lower three bits D0-D2 signal of the data bus to judge the health status of the AC230V three-phase power supply. If a high level 1 is collected, it is considered that AC230V is detected and the three-phase power supply is in a healthy state. If a low level 0 is collected, it is considered that no AC230V is detected and the three-phase power supply is in an unhealthy state.

[0027] The above is an excellent implementation mode of the present invention. It should be pointed out that for ordinary technicians in this technical field, several changes and modifications can be made without departing from the technical principles of the present invention. These changes and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A three-phase AC230V power supply health detection circuit for airborne products, characterized in that: include: The invention discloses a three-way step-down circuit with an isolation transformer, a three-way rectifier filter circuit, a three-way hysteresis comparator circuit, an output buffer circuit, and a CPU processor, wherein the three-way step-down circuit with an isolation transformer respectively receives the line voltage of the three-phase AC power; the output end of the step-down circuit with the isolation transformer is connected to the input end of the corresponding rectifier filter circuit, and the output end of the rectifier filter circuit is connected to the in-phase input end of the corresponding hysteresis comparator circuit; the inverting input end of the hysteresis comparator circuit is connected to the threshold reference voltage; the output end of the hysteresis comparator circuit is connected to the input end of the output buffer circuit, and the output data and control commands of the output buffer circuit are simultaneously input to the CPU processor.

2. The three-phase AC 230V power supply health detection circuit for airborne products according to claim 1 is characterized in that: The three step-down circuits with isolation transformers are the same. The first step-down circuit with isolation transformer includes: resistor RB1, resistor RB2, resistor R5, and transformer T1, wherein one end of the primary side of transformer T1 is connected to one end of resistor RB2 and one end of resistor R5; the other end of resistor RB2 is connected to one end of resistor RB1; the other end of resistor RB1 is connected to the A-phase input end of three-phase alternating current; the other end of resistor R5 and the other end of the primary side of transformer T1 are connected to the B-phase input end of three-phase alternating current.

3. The three-phase AC 230V power supply health detection circuit for airborne products according to claim 1 is characterized in that: The three rectifier and filter circuits have the same structure. The first rectifier and filter circuit includes: a diode D1, a capacitor C1, a resistor RB3, and a capacitor C2, wherein one end of the secondary side of the transformer T1 is connected to the anode of the diode D1; the cathode of the diode D1 is connected to one end of the capacitor C1, one end of the resistor RB3, and one end of the capacitor C2; the other end of the capacitor C1, the other end of the resistor RB3, the other end of the capacitor C2, and the other end of the secondary side of the transformer T1 are grounded.

4. The three-phase AC 230V power supply health detection circuit for airborne products according to claim 1 is characterized in that: The three hysteresis comparator circuits have the same structure. The first hysteresis comparator circuit includes: a resistor R4, a resistor R6, a resistor R3, and a comparator IC1B, wherein the non-inverting input terminal of the comparator IC1B is connected to one end of the resistor R4 and one end of the resistor R6, and the other end of the resistor R4 is connected to the cathode of the diode D1; the reverse input terminal of the comparator IC1B is connected to the output terminal of the bridge voltage divider circuit; the output terminal of the comparator IC1B is connected to the other end of the resistor R6 and one end of the resistor R3; and the other end of the resistor R3 is connected to the DC power supply VCC.

5. The three-phase AC 230V power supply health detection circuit for airborne products according to claim 4 is characterized in that: The bridge voltage divider circuit includes a resistor R1 and a resistor R2, wherein one end of the resistor R1 is connected to one end of the resistor R2, the other end of the resistor R1 is connected to a DC power supply VCC, and the other end of the resistor R2 is grounded.

6. The three-phase AC 230V power supply health detection circuit for airborne products according to claim 4 is characterized in that: The transformer has a turns ratio of 1:1, and the three-phase AC power and signal isolation is achieved through the transformer to improve the product's anti-interference ability.

7. The three-phase AC 230V power supply health detection circuit for airborne products according to claim 4 is characterized in that: By adjusting the parameters of the rectifier and filter circuit, the acquisition delay of the three-phase AC230V power supply health detection circuit can be reduced to less than 100us.

8. The three-phase AC 230V power supply health detection circuit for airborne products according to claim 4 is characterized in that: The phase voltage acquisition interval is set by adjusting the hysteresis comparator circuit parameters.

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