Power frequency charger based on ARM control

Abstract

The utility model discloses a power frequency charger based on ARM control, which comprises a power main circuit and an ARM-based control circuit, the power main circuit comprises an AC input module, a step-down transformer, a rectification circuit and a filter circuit which are electrically connected in sequence, and the ARM-based control circuit comprises an isolation sampling circuit and an ARM control unit. The rectification circuit is a silicon controlled rectifier three-phase full-bridge rectification circuit, the ARM control unit obtains trigger angles of silicon controlled rectifiers in the silicon controlled rectifier three-phase full-bridge rectification circuit according to signals fed back by the isolation sampling circuit, and output voltage is adjusted according to different trigger angles of the silicon controlled rectifiers. The system has the advantages of being good in controllability, convenient to upgrade and maintain, easy to expand, high in precision and good in flexibility.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronics, in particular to an industrial frequency charger based on ARM control. Background Art

[0002] A charger is a power system that converts AC power into DC power. Thyristor controlled rectifier technology controls the output voltage by controlling the trigger angle a, that is, controlling the starting phase of the trigger pulse. Currently, dedicated integrated chips such as the KJ series and KC series are commonly used in China to drive thyristors. These chips are not programmable, have poor controllability, are difficult to expand, upgrade and repair, and are analog chips with errors caused by temperature drift and aging that are difficult to overcome in analog circuits, and cannot guarantee high accuracy and reliability of output. Utility Model Content

[0003] In view of the above technical problems, the utility model provides an ARM-controlled industrial frequency charger which is programmable, highly controllable and easily expandable.

[0004] An embodiment of the utility model provides an industrial frequency charger based on ARM control, including a power main circuit and an ARM-based control circuit, wherein the power main circuit includes an AC input module, a step-down transformer, a rectifier circuit and a filter circuit electrically connected in sequence, and the ARM-based control circuit includes an isolation sampling circuit and an ARM control unit, wherein the rectifier circuit is a thyristor three-phase full-bridge rectifier circuit, and the ARM control unit obtains the trigger angle of the thyristor in the thyristor three-phase full-bridge rectifier circuit according to the signal fed back by the isolation sampling circuit, and adjusts the output voltage by the difference of the thyristor trigger angle.

[0005] Optionally, the ARM-based control circuit also includes a pulse generating circuit, and the ARM control unit obtains the trigger angle of the thyristor in the thyristor three-phase full-bridge rectifier circuit according to the signal fed back by the isolation sampling circuit, and controls the timing of the pulse generating circuit to generate pulses through the thyristor trigger angle, thereby controlling the output voltage.

[0006] Optionally, the filter circuit is an output LC filter circuit.

[0007] Optionally, the ARM-based control circuit further includes a synchronization signal detection circuit, which is connected to a three-phase AC power supply to detect an input power phase sequence and calibrate a synchronization signal.

[0008] Optionally, the ARM-based control circuit further includes a switch input signal circuit and a switch output signal circuit, wherein the switch input signal circuit is connected to the input end of the ARM control unit, and the switch output signal circuit is connected to the output end of the ARM control unit.

[0009] Optionally, the ARM-based control circuit further includes a communication circuit, which is connected to the ARM control unit to transmit the collected internal data of the ARM control unit to an external display device for display.

[0010] Optionally, the ARM-based control circuit also includes an auxiliary power supply circuit, which is respectively connected to the ARM control unit, the switch output signal circuit, the isolation sampling circuit, the pulse generating circuit and the communication circuit to provide electrical energy therefor.

[0011] Optionally, the ARM control unit includes an STM32G474VET6 chip.

[0012] Optionally, the isolation sampling circuit includes a battery voltage isolation detection circuit, a battery current isolation detection circuit, a load voltage isolation detection circuit and a load current isolation detection circuit.

[0013] Optionally, the synchronization signal detection circuit includes a first comparator, a second comparator, a third comparator, a first coupler, a second coupler and a third coupler, the first comparator is connected to the first coupler for comparing the first item of the three-phase alternating current, the second comparator is connected to the second coupler for comparing the second item of the three-phase alternating current, and the third comparator is connected to the third coupler for comparing the third item of the three-phase alternating current.

[0014] In the technical solution provided by the embodiment of the utility model, the ARM-based control circuit includes an isolated sampling circuit and an ARM control unit. The output end of the isolated sampling circuit is connected to the ARM control unit. The ARM control unit controls the output voltage value according to the signal fed back by the isolated sampling circuit. Compared with the prior art, the utility model has the advantages of good controllability, convenient upgrading and maintenance, easy expansion, high precision and good flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The utility model is a circuit diagram of an industrial frequency charger based on ARM control.

[0016] Figure 2 It is a circuit diagram of the main power circuit of the utility model.

[0017] Figure 3 The figure is a circuit diagram of the synchronization signal detection circuit of the utility model.

[0018] Figure 4 It is a circuit diagram of the isolation sampling circuit of the utility model.

[0019] Figure 5 The utility model is a circuit diagram of a pulse generating circuit.

[0020] Figure 6 The figure is a circuit diagram of the switch quantity input signal circuit of the utility model.

[0021] Figure 7 The figure is a circuit diagram of the switch output signal circuit of the utility model. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Please refer to Figure 1 , Figure 2 As shown, the utility model provides an industrial frequency charger based on ARM control, including a power main circuit and an ARM-based control circuit, wherein the power main circuit includes an AC input module, a step-down transformer T1, a rectifier circuit 90 and a filter circuit 80 electrically connected in sequence, and the ARM-based control circuit includes an isolation sampling circuit 30 and an ARM control unit 10, wherein the rectifier circuit 90 is a thyristor three-phase full-bridge rectifier circuit, and the ARM control unit 10 obtains the trigger angle of the thyristor in the thyristor three-phase full-bridge rectifier circuit according to the signal fed back by the isolation sampling circuit 30, and adjusts the output voltage by the difference of the thyristor trigger angle.

[0025] In one embodiment of the present invention, the filter circuit 80 is an output LC filter circuit. The 415V high voltage electricity input by the AC input module is converted into 135V low voltage electricity through the step-down transformer T1, and then passes through the thyristor three-phase full-bridge rectifier circuit 90 to obtain a DC voltage, and then passes through the output LC filter circuit 80 for filtering to obtain a smooth DC voltage.

[0026] Please refer to Figure 2The figure shows a circuit diagram of the main power circuit. The main power circuit includes an AC contactor XT1, a step-down transformer T1, fuses FU1-FU3, a thyristor three-phase full-bridge rectifier circuit 80, an LC filter circuit 80, a fuse FU5 and a circuit breaker QF2. The power input by the AC input module is transmitted to the step-down transformer T1 through the AC contactor XT1. The step-down transformer T1 steps down the input 415V AC voltage to 135V, and then passes through fuses FU1-FU3 for overcurrent protection, and outputs to the thyristor three-phase full-bridge rectifier circuit 80. The AC power is converted into DC power through this circuit, and then filtered through the LC filter circuit 80, and then passes through the fuse FU5 and the circuit breaker QF2 to the DC output terminal.

[0027] In one embodiment of the present utility model, the ARM-based control circuit specifically includes an isolated sampling circuit 30, an ARM control unit 10, a pulse generating circuit 20, a synchronization signal detection circuit, a switch input signal circuit 40, a switch output signal circuit 50, a communication circuit 60 and an auxiliary power supply circuit 70. The auxiliary power supply circuit 70 adopts a 24V DC power supply, and the working current is 500mA to 1500mA, which is used to provide 5V and 3.3V power supplies. The auxiliary power supply circuit 70 is respectively connected to the ARM control unit 10, the switch output signal circuit 50, the isolated sampling circuit 30, the pulse generating circuit 20 and the communication circuit 60 to provide electrical energy for them; the communication circuit 60 is connected to the ARM control unit 10, and the collected ARM control unit 10's internal data is transmitted to an external display device for display; the switch input signal circuit 40 is connected to the input end of the ARM control unit 10, and the switch output signal circuit 50 is connected to the output end of the ARM control unit 10; the synchronization signal detection circuit is connected to a three-phase AC power supply, detects the input power phase sequence, and calibrates the synchronization signal; the isolation sampling circuit 30 includes a battery voltage isolation detection circuit, a battery current isolation detection circuit, a load voltage isolation detection circuit, and a load current isolation detection circuit; the ARM control unit 10 obtains the trigger angle of the thyristor of the thyristor three-phase full-bridge rectifier circuit 90 according to the signal fed back by the isolation sampling circuit 30, and controls the timing of the pulse generation circuit to send pulses through the trigger angle of the thyristor, thereby controlling the output voltage.

[0028] In one embodiment of the present invention, the ARM control unit includes an STM32G474VET6 chip.

[0029] Please refer to Figure 3The circuit diagram of the synchronous signal detection circuit is shown, and the synchronous signal detection circuit includes a first comparator, a second comparator, a third comparator, a first coupler, a second coupler and a third coupler. The first comparator is connected to the first coupler for comparing the first item of the three-phase alternating current, the second comparator is connected to the second coupler for comparing the second item of the three-phase alternating current, and the third comparator is connected to the third coupler for comparing the third item of the three-phase alternating current. The input of the synchronous signal detection circuit is a three-phase alternating current signal. The three signals are compared in pairs by the comparator to generate three isolated switch signals and transmit them to the ARM control unit. The ARM control unit determines the phase information of each phase according to the switch signal for phase shift angle control.

[0030] Specifically, the first comparator, the second comparator and the third comparator are all LM2901 comparators, wherein the first comparator U13A is used to compare the A phase and the C phase of the three AC signals, the second comparator U13B is used to compare the A phase and the B phase of the three AC signals, and the third comparator U13C is used to compare the B phase and the C phase of the three AC signals. When the A phase voltage of the first comparator U13A is higher than the C phase voltage, the first comparator U13A outputs a high level, so that the first optical coupler OC3 will work and output a high level. The other two comparators also work in this way. In this way, the phase relationship of the three-phase electricity can be judged according to the timing of the high level.

[0031] Please refer to Figure 4 The figure shows a circuit diagram of an isolated sampling circuit, which includes a battery voltage isolation detection circuit, a battery current isolation detection circuit, a load voltage isolation detection circuit and a load current isolation detection circuit. The battery voltage isolation detection circuit uses a DC three-wire access and two-way isolation detection, and can judge a single-pole grounding fault while sampling. Under normal circumstances, the impedance between the positive input of the signal end and the ground, and between the negative input and the ground is balanced. At this time, the two related voltages VO and VM collected are in a fixed ratio. When the resistance of one of the poles to the ground changes, this ratio will shift. At this time, the grounding fault can be judged according to the size of the offset value.

[0032] Please refer to Figure 5 The figure shows a circuit diagram of a pulse generating circuit, which uses a forward pulse transformer secondary output. The pulse control signal of the ARM control unit controls the switch of the MOS tube Q70, and at the same time controls the primary pulse current of the pulse transformer TR1. The transformer TR1 then isolates and couples the primary signal to the secondary side. The secondary pulse is then waveform-shaped and output to the thyristor three-phase full-bridge rectifier circuit as a trigger pulse. The control board uses a high-power and high-reliability potted pulse transformer, which has high output pulse power, stable waveform, low heat generation and high reliability.

[0033] Please refer to Figure 6 , Figure 7 The figure shows a circuit diagram of a switch quantity input signal circuit and a switch quantity output signal circuit, wherein the switch quantity input signal circuit includes a photoelectric coupler and the switch quantity output signal circuit includes a relay.

[0034] The industrial frequency charger based on ARM control described in the utility model has the advantages of good controllability, convenient upgrading and maintenance, easy expansion, high precision and good flexibility.

[0035] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An industrial frequency charger based on ARM control, characterized in that: It includes a power main circuit and an ARM-based control circuit. The power main circuit includes an AC input module, a step-down transformer, a rectifier circuit and a filter circuit which are electrically connected in sequence. The ARM-based control circuit includes an isolation sampling circuit and an ARM control unit. The rectifier circuit is a thyristor three-phase full-bridge rectifier circuit. The ARM control unit obtains the trigger angle of the thyristor in the thyristor three-phase full-bridge rectifier circuit according to the signal fed back by the isolation sampling circuit, and adjusts the output voltage by the difference of the thyristor trigger angle.

2. The power frequency charger based on ARM control according to claim 1 is characterized in that: The ARM-based control circuit also includes a pulse generating circuit. The ARM control unit controls the timing of the pulse generating circuit to generate pulses through the thyristor trigger angle, thereby controlling the output voltage.

3. The power frequency charger based on ARM control according to claim 1, characterized in that: The filter circuit is an output LC filter circuit.

4. The power frequency charger based on ARM control according to claim 1, characterized in that: The ARM-based control circuit also includes a synchronization signal detection circuit, which is connected to a three-phase AC power supply to detect the input power phase sequence and calibrate the synchronization signal.

5. The industrial frequency charger based on ARM control according to claim 1, characterized in that: The ARM-based control circuit also includes a switch input signal circuit and a switch output signal circuit, wherein the switch input signal circuit is connected to the input end of the ARM control unit, and the switch output signal circuit is connected to the output end of the ARM control unit.

6. The industrial frequency charger based on ARM control according to claim 1, characterized in that: The ARM-based control circuit also includes a communication circuit, which is connected to the ARM control unit and transmits the collected internal data of the ARM control unit to an external display device for display.

7. The industrial frequency charger based on ARM control according to claim 1, characterized in that: The ARM-based control circuit also includes an auxiliary power supply circuit, which is respectively connected to the ARM control unit, the switch output signal circuit, the isolation sampling circuit, the pulse generating circuit and the communication circuit to provide electrical energy therefor.

8. The industrial frequency charger based on ARM control according to claim 1, characterized in that: The ARM control unit includes an STM32G474VET6 chip.

9. The industrial frequency charger based on ARM control according to claim 1, characterized in that: The isolation sampling circuit includes a battery voltage isolation detection circuit, a battery current isolation detection circuit, a load voltage isolation detection circuit and a load current isolation detection circuit.

10. The industrial frequency charger based on ARM control according to claim 4, characterized in that: The synchronization signal detection circuit includes a first comparator, a second comparator, a third comparator, a first coupler, a second coupler and a third coupler. The first comparator is connected to the first coupler and is used to compare the first item of the three-phase alternating current. The second comparator is connected to the second coupler and is used to compare the second item of the three-phase alternating current. The third comparator is connected to the third coupler and is used to compare the third item of the three-phase alternating current.

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