Coil driving circuit of high-voltage alternating-current and direct-current contactor

Abstract

The utility model discloses a high voltage AC / DC contactor coil drive circuit, which comprises a power supply input module, a power supply rectification voltage reduction module, a voltage detection module, a CPU, a pulse width modulation output module, a current detection module and a contactor coil, and the power supply input module is respectively connected with the input end of the power supply rectification voltage reduction module and the input end of the voltage detection module. The high-voltage AC / DC contactor coil driving circuit is used for uniformly controlling AC and DC contactors, and utilizes voltage detection and pulse width modulation technologies to control the operation power of the contactor coil, prolong the service life of the contactor and reduce the energy consumption.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy, in particular to a high-voltage AC / DC contactor coil drive circuit. Background Art

[0002] The country is vigorously developing the new energy market. Now there are more and more new energy products. The main circuit voltage of these products is generally greater than 200V, and may reach about 400V, or even higher. In this case, the market for high-voltage DC contactors and high-voltage AC contactors is vast. They can play the role of high-voltage disconnecting circuits and are the core switch components of new energy products. There are also many drive control circuits, some for controlling AC contactors and some for controlling DC contactors. Based on this demand, the utility model proposes an innovative structure. Summary of the invention

[0003] The purpose of the utility model is to provide a high voltage AC / DC contactor coil drive circuit to solve the problems raised in the above background technology.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A high-voltage AC / DC contactor coil drive circuit comprises a power input module, a power rectifier and buck module, a voltage detection module, a CPU, a pulse width modulation output module, a current detection module and a contactor coil. The power input module is respectively connected to the input end of the power rectifier and buck module and the input end of the voltage detection module. The output end of the power rectifier and buck module and the output end of the voltage detection module are both connected to the CPU. The CPU is also connected to the contactor coil via the pulse width modulation output module. The current detection module collects the current signal of the contactor coil and transmits it to the CPU.

[0006] As a further technical solution of the utility model: the power rectifier and buck module includes a chip U1, a transformer T1, a resistor R0, a resistor R1 and a capacitor C1, one end of the resistor R0 is connected to the AC live wire L, the other end of the resistor R0 is connected to the resistor R20, the resistor R1, the capacitor C1, the capacitor C9 and the interface 1 of the transformer T1, the other end of the resistor R1 is connected to the other end of the capacitor C1, the other end of the capacitor C10, the resistor R21, the interface 2 of the transformer T1 and the AC neutral line N, the other end of the resistor R20 is connected to the other end of the resistor R21 and the diode D8, the other end of the diode D8 is connected to the other end of the capacitor C9, the other end of the capacitor C10 and the ground, the interface 3 of the transformer T1 is connected to the positive electrode of the diode D1, the positive electrode of the diode D11 and the negative electrode of the diode D12, the negative electrode of the diode D1 is connected to the negative electrode of the diode D2, the positive electrode of the diode D2 is connected to the negative electrode of the diode D13, the diode D14 is connected to the positive electrode of the diode D15, the positive electrode of the diode D16 is connected to the negative electrode of the diode D17, and the positive electrode of the diode D18 is connected to the negative electrode of the diode D19. The positive electrode of tube D14 is connected to interface 4 of transformer T1, the positive electrode of diode D12 is connected to the positive electrode of diode D13, capacitor C0, capacitor C2, capacitor C4, resistor R5, the positive electrode of diode D5 and the ground terminal, the negative electrode of diode D11 is connected to the negative electrode of diode D14, the positive electrode of diode D4, the other end of capacitor C0 and voltage VCC, the negative electrode of diode D4 is connected to the other end of capacitor C2 and pins 5-8 of chip U1, pin 3 of chip U1 is connected to capacitor C3, resistor R4, the negative electrode of diode D5 and inductor L1, the other end of resistor R4 is connected to pin 1 of chip U1, pin 2 of chip U1 is connected to the other end of capacitor C3 and the positive electrode of diode D6, the other end of inductor L1 is connected to the positive electrode of diode D6, the other end of resistor R5 and the other end of capacitor C4, the model of chip U1 is HM5011D, resistor R0 is a thermistor with a negative temperature coefficient, and resistor R1 is a varistor.

[0007] As a further technical solution of the utility model: the power supply rectification and voltage reduction module also includes a voltage stabilizing module for converting the 12V voltage into a 5V voltage. The voltage stabilizing module uses a chip U2 for voltage stabilization. The model of the chip U2 is LM7805.

[0008] As a further technical solution of the utility model: the voltage detection module includes a full-wave rectifier circuit, an input power sampling circuit and a comparator circuit. The full-wave rectifier circuit is connected to the input power sampling circuit, and the input power sampling circuit is also connected to the comparator circuit. The rectifier circuit includes a diode D1 and a diode D2. The input power sampling circuit includes resistors R6, R7, R8, R9, R10 and R12. The comparator circuit includes chips U4A and U4B.

[0009] As a further technical solution of the utility model: the pulse width modulation output module includes a power switch chip U5 and a coil drive circuit. The coil drive circuit includes resistors R14, R15, R16 and NMOS tube Q1. Pin 3 of the power switch chip U5 is connected to the gate of the NMOS tube Q1 through the resistor R14. The source of the NMOS tube Q1 is connected to the resistor R24. The drain of the NMOS tube Q1 is connected to the positive electrode of the diode D10. The model of the power switch chip U5 is HM2531.

[0010] As a further technical solution of the utility model: the current detection module includes an operational amplifier U6, a resistor R25 and a resistor R26, pin 3 of the operational amplifier U6 is connected to the resistor R25 and the resistor R26, the other end of the resistor R26 is grounded, and the other end of the resistor R25 is connected to the pin 4 of the operational amplifier U6, and the model of the operational amplifier U6 is LMV321.

[0011] As a further technical solution of the present utility model: the model of the CPU is STC15W408AS.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] The utility model discloses a high voltage AC / DC contactor coil driving circuit, which is used for uniformly controlling both AC and DC contactors, and uses voltage detection and pulse width modulation technology to control the operating power of the contactor coil, thereby extending the service life of the contactor and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the overall principle diagram of the utility model.

[0015] Figure 2 This is the circuit diagram of the power rectifier and step-down module.

[0016] Figure 3 This is the circuit diagram of the voltage regulator module.

[0017] Figure 4 This is the circuit diagram of the voltage detection module.

[0018] Figure 5 This is the circuit diagram of the pulse width modulation output module.

[0019] Figure 6 This is the circuit diagram of the current detection module.

[0020] Figure 7 This is the circuit diagram of the CPU. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the utility model are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] Example 1: Reference Figure 1-7 The high-voltage AC / DC contactor coil driving circuit includes a power input module, a power rectifier and buck module, a voltage detection module, a CPU, a pulse width modulation output module, a current detection module and a contactor coil. The power input module is respectively connected to the input end of the power rectifier and buck module and the input end of the voltage detection module, the output end of the power rectifier and buck module and the output end of the voltage detection module are both connected to the CPU, the CPU is also connected to the contactor coil through the pulse width modulation output module, and the current detection module collects the current signal of the contactor coil and transmits it to the CPU.

[0023] Embodiment 2, on the basis of embodiment 1, the power rectifier and step-down module includes a chip U1, a transformer T1, a resistor R0, a resistor R1 and a capacitor C1, one end of the resistor R0 is connected to the AC live wire L, the other end of the resistor R0 is connected to the resistor R20, the resistor R1, the capacitor C1, the capacitor C9 and the interface 1 of the transformer T1, the other end of the resistor R1 is connected to the other end of the capacitor C1, the other end of the capacitor C10, the resistor R21, the interface 2 of the transformer T1 and the AC neutral line N, the other end of the resistor R20 is connected to the other end of the resistor R21 and the diode D8, the other end of the diode D8 is connected to the other end of the capacitor C9, the other end of the capacitor C10 and the ground, the interface 3 of the transformer T1 is connected to the positive electrode of the diode D1, the positive electrode of the diode D11 and the negative electrode of the diode D12, the negative electrode of the diode D1 is connected to the negative electrode of the diode D2, the positive electrode of the diode D2 is connected to the negative electrode of the diode D13, the diode D14 is connected to the positive electrode of the diode D15, the positive electrode of the diode D16 is connected to the negative electrode of the diode D17, the positive electrode of the diode D18 is connected to the negative electrode of the diode D19, the positive electrode of the diode D20 is connected to the negative electrode of the diode D211, the positive electrode of the diode D212 is connected to the negative electrode of the diode D23, the positive electrode of the diode D213 is connected to the negative electrode of the diode D19, the positive electrode of the diode D2213 is connected to the negative electrode of the diode D113, the positive electrode of the diode D2213 is connected to the negative electrode of the diode D19. The positive electrode of D14 is connected to interface 4 of transformer T1, the positive electrode of diode D12 is connected to the positive electrode of diode D13, capacitor C0, capacitor C2, capacitor C4, resistor R5, the positive electrode of diode D5 and the ground terminal, the negative electrode of diode D11 is connected to the negative electrode of diode D14, the positive electrode of diode D4, the other end of capacitor C0 and voltage VCC, the negative electrode of diode D4 is connected to the other end of capacitor C2 and pins 5-8 of chip U1, pin 3 of chip U1 is connected to capacitor C3, resistor R4, the negative electrode of diode D5 and inductor L1, the other end of resistor R4 is connected to pin 1 of chip U1, pin 2 of chip U1 is connected to the other end of capacitor C3 and the positive electrode of diode D6, the other end of inductor L1 is connected to the positive electrode of diode D6, the other end of resistor R5 and the other end of capacitor C4, the model of chip U1 is HM5011D, resistor R0 is a thermistor with a negative temperature coefficient, and resistor R1 is a varistor.

[0024] Embodiment 2, on the basis of embodiment 1, the power rectifier and voltage reduction module also includes a voltage stabilizing module for converting 12V voltage into 5V voltage, and the voltage stabilizing module adopts chip U2 for voltage stabilization, and the model of chip U2 is LM7805. The voltage detection module includes a full-wave rectifier circuit, an input power sampling circuit and a comparator circuit, the full-wave rectifier circuit is connected to the input power sampling circuit, the input power sampling circuit is also connected to the comparator circuit, the rectifier circuit includes a diode D1 and a diode D2, the input power sampling circuit includes a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10 and a resistor R12, and the comparator circuit includes a chip U4A and a chip U4B. The pulse width modulation output module includes a power switch chip U5 and a coil drive circuit. The coil drive circuit includes resistors R14, R15, R16 and NMOS tube Q1. Pin 3 of the power switch chip U5 is connected to the gate of NMOS tube Q1 through resistor R14. The source of NMOS tube Q1 is connected to resistor R24. The drain of NMOS tube Q1 is connected to the positive electrode of diode D10. The model of the power switch chip U5 is HM2531. The current detection module includes an operational amplifier U6, resistors R25 and R26. Pin 3 of the operational amplifier U6 is connected to resistors R25 and R26. The other end of resistor R26 is grounded. The other end of resistor R25 is connected to pin 4 of the operational amplifier U6. The model of the operational amplifier U6 is LMV321. The model of the CPU is STC15W408AS.

[0025] Here’s how it works:

[0026] Power rectifier and step-down module Figure 2 and 3As shown, the L and N terminals on the left side of the circuit are the AC / DC power supply access terminals. When the DC power supply is connected, L is the positive pole and N is the negative pole. R0 is a thermistor with a negative temperature coefficient. It can reduce the surge current of the circuit board when the circuit is just powered on. R1 is a varistor, which can solve the abnormal high-amplitude voltage fluctuation at the power input end and control the peak voltage within a certain power supply range. When a high voltage surge is caused by lightning, the varistor will be short-circuited, thereby protecting the subsequent circuit. C1 is a safety capacitor, which can suppress the high-frequency differential mode interference of the AC input signal and play a filtering role for the high-frequency signal. C9 / C10 is a safety capacitor, which is connected to the ground wire and can suppress the common-mode interference of the AC input signal. R20, R21 resistors and D8 discharge tube are connected in series and then grounded to form a circuit for discharging common-mode lightning surges. T1 common-mode inductor has the function of bidirectional filtering, which can prevent the high-frequency signal inside the circuit from radiating to the outside and generating EMI interference, and can also prevent the external common-mode signal from entering the circuit, thereby improving the EMC electromagnetic compatibility performance of the circuit. The four diodes D11 / D12 / D13 / D14 are rectifier bridges that convert AC signals into DC signals. The D4 diode protects the subsequent circuit from being damaged by reverse voltage. C0 is a high-frequency filter capacitor, and C2 is a low-frequency filter capacitor.

[0027] U1 controls the power switch chip, R4 / R5 resistors, C3 / C4 capacitors, and D5 / D6 fast recovery diodes form a non-isolated voltage-stabilizing step-down circuit to output a stable 12V DC power supply. The U1 chip integrates the protection functions of the self-recovery function, including VDD undervoltage protection, cycle-by-cycle current limiting, output overvoltage protection, overheat protection, overload protection, and VDD overvoltage protection. U2 low-voltage linear voltage regulator chip and C5 / C6 / C7 / C8 capacitors form a DC-DC conversion circuit to convert 12V from 5V.

[0028] Input voltage detection module such as Figure 4 As shown, the D1 / D2 diodes form a full-wave rectifier circuit to provide a continuous input signal for the back-end resistor sampling circuit. The R6 / R7 / R8 / R9 / R10 / R12 resistors form an input power sampling circuit. The voltage at the top of R12 is 1 / 00 ​​of the total input voltage. This signal is connected to the CPU analog quantity acquisition pin to trigger related instructions. The U4A voltage comparator and the R11 / R12 / R13 resistors form a high-voltage pull-in threshold circuit. When the voltage at pin 2 of the U4A chip is higher than the voltage at pin 3, the chip pin 1 will output a low level to the CPU to trigger related instructions. The U4A voltage comparator and the R12 / R22 / R23 resistors form a low-voltage release threshold circuit. When the voltage at pin 5 of the U4A chip is lower than the voltage at pin 6, the chip pin 7 will output a low level to the CPU to trigger related instructions. The D7 voltage regulator diode clamps the maximum voltage of the back-end circuit to 18V, thereby ensuring that the maximum value of the CPU sampling voltage is 5.2V.

[0029] Pulse width modulation output module such as Figure 5 As shown, the U5 power switch chip, R14 / R15 / R16 resistors, and Q1 NMOS tube form a coil drive circuit. The CPU sends a PWM signal to U5's 1 pin, and U5's 5 pin outputs a phase signal to Q1 tube. When the Q1 tube is high, it is turned on, which can turn on the voltage of the contactor coil. D10 ultra-fast recovery diode protects Q1 tube to prevent reverse breakdown, and when the circuit is disconnected, the current of the contactor coil can continue to form a loop to release residual energy. C12 capacitor is used to filter out high-frequency interference signals on the power supply.

[0030] Coil current detection module such as Figure 6 As shown in the figure, the U6 operational amplifier, R25 / R26 resistors, and R24 resistor in the pulse width modulation output module form the contactor coil current circuit. The voltage generated on the R24 resistor by the current flowing through the contactor coil is amplified to a suitable voltage range through the amplifier circuit composed of U5 / R25 / R26, and output to the CPU acquisition pin to trigger related instructions.

[0031] CPU Figure 7 As shown, U3 is the CPU, which is the core device of the entire circuit for data acquisition, processing and command output. R17 / R18 / R19 resistors and LED1 / LED2 light-emitting diodes form a random number selection and status indication circuit. C11 capacitor is used to filter out high-frequency interference signals on the power supply, and C13 capacitor is used to filter out low-frequency interference signals on the power supply, providing a more stable power supply for the CPU.

[0032] The utility model provides an innovative circuit for uniformly controlling two contactors, an AC contactor and a DC contactor, and uses voltage detection and pulse width modulation technology to control the operating power of the contactor coil, thereby extending the service life of the contactor and reducing energy consumption.

[0033] In the actual use of the contactor control coil, this circuit can meet the AC and DC power input, the AC power range is 50~400V / 50~60Hz, and the DC power range is 30~400VDC.

[0034] In actual circuit control, the circuit generates two-stage output: in the first stage, at the moment when the contactor is started, a square wave signal with a specific interval is output, which has a strong current carrying capacity and a large pull-in power; in the second stage, after the contactor coil is pulled in, it follows the input voltage / current fluctuations and controls the output PWM signal to ensure that the coil is pulled in and maintains low power.

[0035] In actual use, this circuit has threshold detection, and resistors of different resistance values ​​can be flexibly selected to configure the contactor's pull-in voltage and release voltage.

[0036] This circuit is equipped with EMI circuit, and when multiple contactor clusters are working, CPU peak shifting strategy and watchdog anti-crash error correction program can be configured.

[0037] This circuit is practical and reliable, and has been verified by 500,000 action cycles.

[0038] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0039] In addition, it should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment have also been appropriately combined to form other implementation modes that are easy for those skilled in the art to understand.

Claims

1. A high voltage AC / DC contactor coil drive circuit, comprising a power input module, a power rectifier and voltage step-down module, a voltage detection module, a CPU, a pulse width modulation output module, a current detection module and a contactor coil, characterized in that: The power input module is respectively connected to the input end of the power rectifier and buck module and the input end of the voltage detection module, the output end of the power rectifier and buck module and the output end of the voltage detection module are both connected to the CPU, the CPU is also connected to the contactor coil through the pulse width modulation output module, and the current detection module collects the current signal of the contactor coil and transmits it to the CPU.

2. The high voltage AC / DC contactor coil drive circuit according to claim 1, characterized in that: The power rectifier and voltage-reducing module includes a chip U1, a transformer T1, a resistor R0, a resistor R1 and a capacitor C1, one end of the resistor R0 is connected to an AC live wire L, the other end of the resistor R0 is connected to a resistor R20, a resistor R1, a capacitor C1, a capacitor C9 and an interface 1 of the transformer T1, the other end of the resistor R1 is connected to the other end of the capacitor C1, the other end of the capacitor C10, a resistor R21, an interface 2 of the transformer T1 and an AC neutral line N, the other end of the resistor R20 is connected to the other end of the resistor R21 and a diode D8, the other end of the diode D8 is connected to the other end of the capacitor C9, the other end of the capacitor C10 and a ground terminal, the interface 3 of the transformer T1 is connected to the positive electrode of the diode D1, the positive electrode of the diode D11 and the negative electrode of the diode D12, the negative electrode of the diode D1 is connected to the negative electrode of the diode D2, the positive electrode of the diode D2 is connected to the negative electrode of the diode D13, the positive electrode of the diode D14 and Interface 4 of transformer T1, the anode of diode D12 is connected to the anode of diode D13, capacitor C0, capacitor C2, capacitor C4, resistor R5, the anode of diode D5 and the ground terminal, the cathode of diode D11 is connected to the cathode of diode D14, the anode of diode D4, the other end of capacitor C0 and voltage VCC, the cathode of diode D4 is connected to the other end of capacitor C2 and pins 5-8 of chip U1, pin 3 of chip U1 is connected to capacitor C3, resistor R4, the cathode of diode D5 and inductor L1, the other end of resistor R4 is connected to pin 1 of chip U1, pin 2 of chip U1 is connected to the other end of capacitor C3 and the anode of diode D6, the other end of inductor L1 is connected to the anode of diode D6, the other end of resistor R5 and the other end of capacitor C4, the model of chip U1 is HM5011D, resistor R0 is a thermistor with a negative temperature coefficient, and resistor R1 is a varistor.

3. The high voltage AC / DC contactor coil drive circuit according to claim 2, characterized in that: The power supply rectification and voltage reduction module also includes a voltage stabilizing module for converting the 12V voltage into a 5V voltage. The voltage stabilizing module uses a chip U2 for voltage stabilization. The model of the chip U2 is LM7805.

4. The high voltage AC / DC contactor coil drive circuit according to claim 1, characterized in that: The voltage detection module includes a full-wave rectifier circuit, an input power sampling circuit and a comparator circuit. The full-wave rectifier circuit is connected to the input power sampling circuit, and the input power sampling circuit is also connected to the comparator circuit. The rectifier circuit includes a diode D1 and a diode D2. The input power sampling circuit includes resistors R6, R7, R8, R9, R10 and R12. The comparator circuit includes chips U4A and U4B.

5. The high voltage AC / DC contactor coil drive circuit according to claim 1, characterized in that: The pulse width modulation output module includes a power switch chip U5 and a coil drive circuit. The coil drive circuit includes resistors R14, R15, R16 and an NMOS tube Q1. Pin 3 of the power switch chip U5 is connected to the gate of the NMOS tube Q1 through the resistor R14. The source of the NMOS tube Q1 is connected to the resistor R24. The drain of the NMOS tube Q1 is connected to the positive electrode of the diode D10. The model of the power switch chip U5 is HM2531.

6. The high voltage AC / DC contactor coil drive circuit according to claim 1, characterized in that: The current detection module includes an operational amplifier U6, a resistor R25 and a resistor R26, wherein pin 3 of the operational amplifier U6 is connected to the resistors R25 and R26, the other end of the resistor R26 is grounded, and the other end of the resistor R25 is connected to pin 4 of the operational amplifier U6, and the model of the operational amplifier U6 is LMV321.

7. The high voltage AC / DC contactor coil drive circuit according to claim 1, characterized in that: The model of the CPU is STC15W408AS.

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