Double-path shunt release control circuit

Abstract

The utility model relates to a double-path shunt release control circuit, which comprises two shunt release channels, a power supply generation module and a signal processing and grid driving module, and each shunt release channel comprises a filter rectifier module, an input detection module and a release coil driving module. According to the utility model, one control circuit is adopted to control two shunt trip coils, so that the size is smaller, the installation is convenient, and the cost is lower; the functions of the two paths of the double-path shunt release are independent of each other and do not interfere with each other. The power supply module and the signal processing and grid driving module of the double-path shunt release circuit are shared, at least one path of external input can be electrified to work after being loaded, the compatibility is strong, and compared with an independent double-path shunt release, the control circuit is compact and the cost is lower; the signal processing and gate driving module adopts the technologies of digital filtering, digital hysteresis comparison and the like, on one hand, the anti-interference performance can be improved, and on the other hand, the tripping time sequence can be accurately controlled.

Description

Technical Field

[0001] The utility model belongs to the technical field of shunt releasers, and in particular relates to a double-path shunt releaser control circuit. Background Art

[0002] Shunt release (undervoltage release) refers to a relay that causes the mechanical switch to open or close with or without delay when the terminal voltage of the relay or release drops to a predetermined value. The release is combined with the switch. When the external voltage drops, even slowly drops to 70% to 35% of the rated voltage, the undervoltage release combined with the switch should operate to disconnect the appliance.

[0003] The existing shunt release control circuit generally adopts two independent control circuits for control, which has a large overall volume and high manufacturing cost. Utility Model Content

[0004] In view of the problems existing in the prior art, the utility model provides a dual-path shunt release control circuit. The dual-path release control circuit can detect two-path input signals simultaneously and control two release coils respectively.

[0005] The utility model provides a dual-channel shunt release control circuit, including two shunt release channels, a power generation module and a signal processing and gate drive module, wherein the shunt release channel includes a filter rectifier module, an input detection module and a release coil drive module;

[0006] The power generation module is respectively connected to the filter and rectifier module, the input detection module, and the trip coil drive module to supply power to them;

[0007] The filtering and rectifying module is connected to the zero-fire input module and is used to perform full-wave rectification on the input signal;

[0008] The input detection module is connected to the filter and rectifier module, and is used to convert the rectified signal into a smooth low-voltage signal;

[0009] The signal processing and gate driving module is connected to the input detection module and the trip coil driving module respectively, and is used to generate the driving signal required by the trip coil driving module to control the action of the trip coil.

[0010] In a preferred embodiment of the utility model, the filtering and rectifying module includes a varistor, a common-mode inductor, a fuse resistor, a thermistor and a rectifier bridge, the common-mode inductor is connected to the varistor, the fuse resistor and the thermistor are respectively connected to the common-mode inductor, and the rectifier bridge is respectively connected to the fuse resistor and the thermistor.

[0011] In a preferred embodiment of the utility model, the input detection module includes a voltage-dividing resistor, a low-pass filter circuit and a Zener diode, the voltage-dividing resistor is connected to the input signal, and the low-pass filter circuit is respectively connected to the voltage-dividing resistor and the Zener diode.

[0012] In a preferred embodiment of the utility model, the power generation module includes a current limiting resistor, a power switch tube and a linear voltage regulator, the current limiting resistor is connected to the input signal, and the power switch tube is respectively connected to the linear voltage regulator.

[0013] In a preferred embodiment of the present utility model, the signal processing and gate driving module includes a signal processing module and a gate driving module;

[0014] The signal processing module is implemented by a single chip microcomputer, and includes an analog-to-digital converter, a low-pass filter, a hysteresis comparator, a side pressure detector and a timing controller. The analog-to-digital converter is connected to the low-pass filter, the low-pass filter is connected to the hysteresis comparator or the side pressure detector, and the hysteresis comparator and the side pressure detector are respectively connected to the timing controller;

[0015] The gate driving module is implemented by a totem pole or a dedicated gate driving chip.

[0016] In a preferred embodiment of the present invention, the trip coil driving module includes a connected diode, a MOS tube and a capacitor.

[0017] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0018] (1) One control circuit is used to control two shunt trip coils, which is smaller in size, easier to install, and thus lower in cost.

[0019] (2) The two functions of the dual-circuit shunt release are independent of each other and there is no interference.

[0020] (3) The power module and signal processing of the dual-channel shunt release circuit are shared with the gate drive module. It can be powered on and work after at least one external input is loaded, and has strong compatibility. Compared with independent two-channel shunt releases, the control circuit is compact and the cost is lower.

[0021] (4) The signal processing and gate drive module adopts technologies such as digital filtering and digital hysteresis comparison, which can improve the anti-interference performance on the one hand and accurately control the tripping timing on the other hand. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a simplified structural diagram of the control circuit of the dual-circuit shunt release of the utility model;

[0023] Figure 2 It is a principle block diagram of the control circuit of the dual-circuit shunt release of the utility model;

[0024] Figure 3 This is a principle block diagram of the filter and rectifier module of the utility model;

[0025] Figure 4 It is a waveform diagram of the filter and rectifier module of the utility model;

[0026] Figure 5 It is a principle block diagram of the input detection module of the utility model;

[0027] Figure 6 It is a waveform diagram of the input detection module of the utility model;

[0028] Figure 7 This is a principle block diagram of the power generation module of the utility model;

[0029] Figure 8 are the input and output waveforms of the power generation module of the utility model;

[0030] Fig. 9 It is a principle block diagram of the signal processing module of the utility model;

[0031] Fig.10 It is a key node waveform diagram of the signal processing module of the utility model;

[0032] Fig.11 This is a principle block diagram of the gate drive module of the utility model;

[0033] Fig.12 It is a principle block diagram of the trip coil drive module of the utility model. DETAILED DESCRIPTION

[0034] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings.

[0035] The structure of the utility model is described in detail below in conjunction with the accompanying drawings.

[0036] like Figure 1 A dual-circuit shunt release control circuit is shown, and the dual-circuit shunt release control circuit has two shunt release channels, which are respectively connected to two release coils (trip coil 1 and trip coil 2), and the input ends of the two shunt release channels are respectively connected to two zero-fire inputs (zero-fire input 1 and zero-fire input 2).

[0037] Specifically, combined Figure 2As shown, the dual-channel shunt release control circuit includes two shunt release channels (shunt release channel 1, shunt release channel 2), a power generation module, and a signal processing and gate drive module, wherein the shunt release channel includes a filter rectifier module, an input detection module, and a trip coil drive module, the input signal typical value is 220V50Hz, and the common modules of the dual-channel shunt release control circuit are power generation, signal processing, and gate drive.

[0038] The power generation module is respectively connected to the filter rectifier module, the input detection module, and the trip coil drive module, and supports two inputs at the same time or only one input.

[0039] The power generation module generates two power supplies: one is used for the power supply of the trip coil drive, and the typical value of the power supply is about 15V; the other is used for the power supply of the signal processing, and the typical value is 5V.

[0040] Signal processing and gate drive module: When zero-fire input is used as input signal, it is detected by this module and processed, and converted into the driving signal required by the trip coil driver through the gate drive circuit to control the action of the trip coil.

[0041] Combination Figure 3 As shown, the filter rectifier module consists of two channels. The components of the input filter circuit are varistor MOV, common mode inductor L0, fuse resistor R0, thermistor NTC, and rectifier bridge. The common mode inductor L0 is connected to the varistor MOV, the fuse resistor R0 and the thermistor NTC are connected to the common mode inductor L0 respectively, and the rectifier bridge is connected to the fuse resistor R0 and the thermistor NTC respectively.

[0042] The varistor MOV is used to prevent lightning strikes and surges from damaging the rear devices. The common mode inductor L0 is used to reduce conducted and radiated interference. The fuse resistor R0 is used to reduce the instantaneous current at power-on and provide current protection. The thermistor NTC is used to control the magnitude of the instantaneous current at power-on and protect the circuit. The rectifier bridge uses bridge rectification to achieve full-wave rectification.

[0043] The waveform of the dual-channel filter rectifier circuit is as follows: Figure 4 As shown, the AC input signal is rectified to output two signals VH1 and VH2.

[0044] Combination Figure 5As shown, the input detection module includes voltage-dividing resistors R1, R2, R3, R4, a low-pass filter circuit and Zener diodes Z1 and Z2, and the input signals of the input detection module are VH1 and VH2. The voltage-dividing resistors R1 and R2 are used for voltage division to convert the rectified signals into low-voltage signals SN1 and SN2. RN1 and C1 form a low-pass filter circuit to obtain a smoother signal SA1, and output SA1 to the signal processing module. Similarly, the voltage-dividing resistors R3 and R4 are used for voltage division, and RN2 and C2 form a low-pass filter circuit to obtain a smoother signal SA2, and output SA1 to the signal processing module. Zener diodes Z1 and Z2 are used for port protection to limit the amplitude of SA1 and SA2 to not exceed the maximum input range of the subsequent circuit.

[0045] The waveform of the input detection module is as follows: Figure 6 As shown, VH1 and VH2 are waveforms after full-wave rectification, SN1 and SN2 are waveforms after resistor voltage division, and SA1 and SA2 are waveforms after filtering. The DC levels of SN1 and SN2 gradually increase to the resistor voltage division value of the effective value of VH1 and VH2. Similarly, the DC levels of SA1 and SA2 also gradually increase and reach a stable value after a period of time.

[0046] Power generation module circuit compatible with dual input such as Figure 7 As shown, it includes current limiting resistors R5, R6, a power switch tube T1 and a linear regulator LDO.

[0047] The input signals VH1 and VH2 are combined through a diode, which is compatible with normal power supply when two inputs are input at the same time or any one input. R5 is the current limiting resistor of the power branch, and R6 is the current limiting resistor of the voltage regulator branch. T1 is the power switch tube, which can be a triode or a MOS tube. The power generation module circuit generates VPS through a linear power supply circuit, and then generates power VCC through a linear regulator LDO.

[0048] The input and output waveforms of the power generation module are as follows: Figure 8 As shown, VH1 and VH2 are not necessarily powered at the same time, and only one circuit may work. The typical value of the output VPS is about 15V. Since there is only one level of circuit, there is a certain ripple. VPS is used for the power supply of the gate drive to ensure that the switch MOS tube works at a good voltage value. VCC is used for the working power supply of the microcontroller, and the typical value is 5V.

[0049] The signal processing and gate driving module includes a signal processing module and a gate driving module.

[0050] Among them, the signal processing module is implemented by a single chip microcomputer, such as Fig. 9As shown, it includes an analog-to-digital converter, a low-pass filter, a hysteresis comparator, a side pressure detector and a timing controller. Taking one of the channels as an example, the sampling value SA1 of the input signal VH1 is sampled by the analog-to-digital converter (ADC), converted from an analog signal to a digital signal, and then passes through a low-pass filter to filter out high-frequency noise, and obtains SP1 after hysteresis comparison to obtain the rising edge of the control signal. The use of a hysteresis comparator can effectively avoid the zero-crossing oscillation of the comparator, reduce the probability of coil oscillation in the release, and improve reliability. The falling edge of the control signal is generated by the microcontroller (can also be set by the user), thereby obtaining the falling edge of the control signal. Finally, the opening and closing time of the trip coil is obtained.

[0051] In addition, the input signal VH1 is divided by a resistor and converted into a low-voltage SN1. Similarly, it is converted from an analog signal to a digital signal through analog-to-digital conversion, and a low-pass filter is used to filter out high-frequency noise, and edge detection is performed to obtain the zero-crossing signal of the sine wave input, which is equivalent to generating a clock SC1. Under the control of the clock, the opening and closing time of the trip coil is precisely controlled.

[0052] The key node waveform of the signal processing module is as follows: Fig.10 As shown, VH1 is the waveform after the input sine wave is rectified, SA1 is the waveform after the voltage division and filtering of VH1, Sth is set as the threshold of the input voltage, when SA1 reaches Sth, the output waveform is the rising edge SP1. The waveform after the voltage division of VH1 is SN1. By judging the waveform of SN1, the pulse signal SC1 when the sine wave passes through the zero point is obtained, and SC1 is used to control the timing control of the gate signal. The rising edge of the gate drive waveform VG1 of the release is controlled by SP1 and SC1, and it is turned on at the rising edge of SC1. After the delay of the tripping time, the release is closed at the rising edge of SC1 to complete the tripping process.

[0053] The gate drive module of the trip coil can be implemented using a totem pole or a dedicated gate drive chip. The circuit principle block diagram is as follows: Fig.11 As shown, the gate drive signal VG1 with a peak-to-peak value of VCC is converted into a gate drive signal VDG1 with a peak-to-peak value of VPS, ensuring that the MOS switch tube is in a good voltage switching range and that the gate drive provides good MOS drive.

[0054] The circuit diagram of the trip coil drive module is as follows: Fig.12As shown, it includes diodes DD1, DD2, MOS tubes M1, M2, and capacitors CD1, CD2. Among them, MOS tube M1 is controlled by the drive signal VDG1, and is turned on and off when powered on, so that the trip coil is turned on and has the function of shunt tripping. Diode DD1 is a freewheeling diode. When MOS tube M1 is turned off, it provides a current channel for the load coil to ensure reliable operation of the product. Capacitor CD1 is used to improve the EMC performance of the overall circuit.

[0055] The above description is only a preferred embodiment of the utility model, and does not constitute any form of limitation to the utility model. Although the utility model has been disclosed as a preferred embodiment as above, it is not used to limit the utility model. Any technician familiar with this patent will not depart from the scope of the technical solution of the utility model.

Claims

1. A dual-circuit shunt release control circuit, characterized in that: It includes two shunt tripping channels, a power generation module, and a signal processing and gate driving module. The shunt tripping channel includes a filter rectifier module, an input detection module, and a tripping coil driving module; The power generation module is respectively connected to the filter and rectifier module, the input detection module, and the trip coil drive module to supply power to them; The filtering and rectifying module is connected to the zero-fire input module and is used to perform full-wave rectification on the input signal; The input detection module is connected to the filter and rectifier module, and is used to convert the rectified signal into a smooth low-voltage signal; The signal processing and gate driving module is connected to the input detection module and the trip coil driving module respectively, and is used to generate the driving signal required by the trip coil driving module to control the action of the trip coil.

2. The dual-circuit shunt release control circuit according to claim 1, characterized in that: The filtering and rectifying module comprises a varistor, a common-mode inductor, a fuse resistor, a thermistor and a rectifier bridge. The common-mode inductor is connected to the varistor, the fuse resistor and the thermistor are respectively connected to the common-mode inductor, and the rectifier bridge is respectively connected to the fuse resistor and the thermistor.

3. The dual-circuit shunt release control circuit according to claim 1, characterized in that: The input detection module includes a voltage-dividing resistor, a low-pass filtering circuit and a Zener tube. The voltage-dividing resistor is connected to the input signal, and the low-pass filtering circuit is connected to the voltage-dividing resistor and the Zener tube respectively.

4. The dual-circuit shunt release control circuit according to claim 1, characterized in that: The power generation module includes a current limiting resistor, a power switch tube and a linear voltage regulator. The current limiting resistor is connected to an input signal, and the power switch tubes are respectively connected to the linear voltage regulator.

5. The dual-circuit shunt release control circuit according to claim 1, characterized in that: The signal processing and gate driving module includes a signal processing module and a gate driving module; The signal processing module is implemented by a single chip microcomputer, and includes an analog-to-digital converter, a low-pass filter, a hysteresis comparator, a side pressure detector and a timing controller. The analog-to-digital converter is connected to the low-pass filter, the low-pass filter is connected to the hysteresis comparator or the side pressure detector, and the hysteresis comparator and the side pressure detector are respectively connected to the timing controller; The gate driving module is implemented by a totem pole or a dedicated gate driving chip.

6. The dual-circuit shunt release control circuit according to claim 1, characterized in that: The trip coil driving module includes a connected diode, a MOS tube and a capacitor.

Images