CN102545147A - Method for tandem operation of alternating current shunt release and alternating current relay - Google Patents

Abstract

The invention relates to a method for working in series between an AC shunt release and an AC relay, which comprises: after the button switch connected in parallel to the AC intermediate relay is turned on, the sampling circuit samples the unidirectional pulsating DC voltage generated by the rectifier circuit , so that the MCU circuit can obtain the sampling voltage Vsa and the zero-crossing pulse signal SI collected by the sampling circuit and judge whether the unidirectional pulsating DC voltage reaches 60% of the rated voltage value Ue of the shunt electromagnet coil; if it reaches, the MCU circuit outputs A control signal to cut off the strong load circuit, so that the voltage value of the unidirectional pulsating DC voltage rises rapidly, and the MCU circuit generates a single pulse signal lasting 50-60ms when the unidirectional pulsating DC voltage crosses zero, the single pulse signal After being amplified by the drive circuit, the coil of the shunt excitation electromagnet is controlled to be electrically conducted, so that the armature in the AC shunt release works to realize the opening action.

Description

The Method of Working in Series with AC Shunt Release and AC Relay

technical field

The invention relates to a method for an AC shunt release and an AC relay to work in series.

Background technique

The shunt release is used to receive the remote control voltage and is the core component to realize the "remote control" opening of the low-voltage circuit breaker. For example, in civil buildings where fire protection requires a power outage circuit, a circuit breaker with a shunt release can be selected. The fire alarm system can remotely control the opening of the circuit breaker through modules or cables in the fire center.

Existing AC shunt releases are all short-time working systems, and cannot be connected (operated) to the power supply for a long time, and the power-on time generally cannot exceed 1 second, otherwise the coil in the shunt electromagnet coil is easily burned; in addition, if The AC relay is connected in series with the AC shunt release, and the voltage obtained by the AC intermediate relay is too low to work normally due to the series voltage division of the AC relay, so the AC shunt release cannot work in series with the AC relay.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method in which an AC shunt release that can be connected in series with an AC relay and can be energized for a long time works in series with the AC relay.

In order to solve the above technical problems, the present invention provides a method for AC shunt release and AC relay to work in series, including:

①When the button switch connected in parallel to the AC intermediate relay is turned on, the AC input voltage is directly added to the AC input terminal of the rectifier circuit in the AC shunt release, and the rectifier circuit generates a unidirectional pulsating DC voltage; The unidirectional pulsating DC voltage is sent to one end of the strong load circuit, the sampling circuit and the shunt electromagnet coil; after the sampling circuit samples the unidirectional pulsating DC voltage, the MCU circuit is collected by the sampling circuit. The sampling voltage Vsa and the zero-crossing pulse signal SI; the MCU circuit judges whether the unidirectional pulsating DC voltage reaches the rated voltage value Ue of the shunt electromagnet coil work according to the sampling voltage Vsa and the zero-crossing pulse signal SI 60% of 60%; if reached, the MCU circuit outputs a control signal to cut off the heavy load circuit, so that the value of the unidirectional pulsating DC voltage rises rapidly, and the MCU circuit (5) in the single When the pulsating DC voltage crosses zero, a single pulse signal lasting 50-60 ms is generated. After the single pulse signal is amplified by the drive circuit, it controls the conduction of the shunt electromagnet coil to make the AC shunt off The armature in the buckle works to realize the opening action;

② When the button switch is released, the coil of the AC intermediate relay obtains a voltage of more than 90% of the AC input voltage; the MCU circuit judges that the single Whether the pulsating DC voltage is lower than 50% of the rated voltage value Ue of the shunt electromagnet coil; quickly pull down to below 10% of the rated voltage value Ue; and the MCU circuit does not generate the single pulse signal, then the shunt electromagnet coil is not turned on.

The invention has the following advantages: (1) The AC shunt release can work in series with the AC intermediate relay, which broadens the application range of the AC shunt release; (2) Since the load capacitance with very low capacitive reactance is provided, And ensure that the AC relays connected in series have a reliable working voltage; (3) The MCU circuit is used inside, and its own power consumption is extremely low; the MCU circuit can quickly increase or decrease the unidirectional pulsating DC voltage, avoiding the transition caused by the AC relay (4) The shunt electromagnet can be started to work at the AC zero-crossing point, which greatly improves the reliability of the shunt release, plays a zero-crossing protection function, and avoids interference to the power grid; (5) The AC The shunt release has simple circuit, low cost and high reliability.

Description of drawings

In order to make the content of the present invention more easily understood, the present invention will be described in further detail below in conjunction with the specific embodiments according to the accompanying drawings, wherein

Fig. 1 is the structural representation of the AC shunt tripper suitable for series connection with the AC relay of the present invention;

Fig. 2 is the circuit principle diagram of strong load circuit of the present invention;

Fig. 3 is a schematic circuit diagram of the sampling circuit of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the present invention is described in detail:

The parameter design of the AC shunt release of the present invention complies with the low-voltage switchgear and control equipment standards: GB14048.1-2006 and GB14048.2-2008 define the main technical parameters of the release. Under the requirements of this standard, the following examples are given for illustration.

Example 1

See Figures 1, 2, and 3. The AC shunt release of this embodiment is suitable for working in series with the AC intermediate relay. The total input AC voltage of the circuit is ui, and the push button switch is connected in parallel with the AC intermediate relay. The AC shunt release includes: a rectifier circuit 1, a drive circuit 6, a shunt electromagnet coil 9, a load capacitor CL, a strong load circuit 2, a sampling circuit 4, and an MCU circuit 5; the load capacitor CL is connected in parallel to The AC access terminal of the rectifier circuit 1, and the input impedance of the AC shunt release 8 is not greater than 1/10 of the impedance of the AC intermediate relay 7; the positive output terminal of the rectifier circuit 1 is respectively connected to the The voltage input end of the strong load circuit 2, the sampling circuit 4 is connected to one end of the shunt electromagnet coil 9; The ground terminal of the circuit 6 is connected; the sampling circuit 4 samples the unidirectional pulsating DC voltage Ui output by the rectifier circuit 1 to obtain a sampling voltage Vsa and a zero-crossing pulse signal SI, and the MCU circuit 5 according to the sampling voltage Vsa and the zero-crossing pulse signal SI judge whether the unidirectional pulsating DC voltage Ui reaches 60% of the rated voltage value Ue of the shunt electromagnet coil work; if reached, the MCU circuit 5 outputs a control signal to cut off The strong load circuit 2 makes the voltage value of the unidirectional pulsating DC voltage Ui rise rapidly, and the MCU circuit 5 generates a single pulse lasting 50-60ms when the unidirectional pulsating DC voltage Ui crosses zero signal, the single pulse signal is amplified by the drive circuit 6, and controls the shunt electromagnet coil 7 to be electrically conducted, so that the armature in the AC shunt release 8 works to realize the opening action; in addition, The MCU circuit 5 also judges whether the unidirectional pulsating DC voltage Ui is lower than 50% of the rated voltage value Ue of the shunt electromagnet coil 9 according to the sampling voltage Vsa and the zero-crossing pulse signal SI; , then the MCU circuit 5 controls the access of the heavy load circuit 2, so that the unidirectional pulsating DC voltage Ui is quickly pulled down to below 10% of the rated voltage value Ue; and the MCU circuit 5 does not generate The single pulse signal, then the shunt electromagnet coil 7 is not conducted.

The MCU (including SOC, CPLD, FPGA, etc.) used in the present invention can be any type of MCU from any company. The MCU interrupt input channel responds to the rising edge (or falling edge) interrupt of the zero-crossing pulse signal SI, and can calculate the cycle time of the unidirectional pulsating DC voltage Ui (or the cycle of the AC input voltage ui); the MCU simulates The input channel samples and compensates the sampling voltage Vsa signal at 16 points (32 points or 48 points, etc.) according to the cycle time, and calculates the voltage value of the unidirectional pulsating DC voltage Ui. The MCU determines the high and low levels of the strong load control signal according to the magnitude of the effective value, and determines whether to output the single pulse signal lasting 50-60ms.

In the working process of the AC shunt release, because the shunt electromagnet coil has the characteristics similar to the inductance, it is an energy storage element; so the unidirectional pulsating DC connected to it cannot step, and there is a transition process, especially with the Coil-type static voltage relays in series; static voltage relays with integrated circuits inside rely on their own internal relays to achieve their own "moving-off" process, without an "intermediate area". Good cooperation with its work, so the transition process should be avoided during the working process of the AC shunt release. In order to avoid the transition process, a strong load circuit controlled by the MCU circuit is installed in the circuit to make the one-way The pulsating DC voltage can be pulled up or pulled down quickly.

As shown in Fig. 2, the strong load circuit 2 includes: one end of the dummy load resistor JFZ1 is connected to the positive output end of the rectifier circuit 1, and the other end of the dummy load resistor JFZ1 is connected to the drain of the field effect transistor TD1, The gate of the field effect transistor TD1 is connected to the output terminal of the control signal generated by the MCU circuit 5 to the heavy load circuit 2 , and the source of the field effect transistor TD1 is grounded.

A varistor YM for suppressing surge voltage is connected in parallel at the AC access end of the AC shunt release 8 .

As shown in Fig. 3, the sampling circuit 4 includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1 and a three-terminal adjustable shunt reference source T1 One end of the first resistor R1 and the third resistor R3 are connected to the positive output end of the rectifier circuit 1, and the other end of the first resistor R1 is connected to one end of the second resistor R2, and used as the output end of the sampling voltage Vsa , and the other end of the second resistor R2 is grounded; the other end of the third resistor R3 is connected to the fourth resistor R4, one end of the first capacitor C1, and a reference electrode of a three-terminal adjustable shunt reference source T1, The other end of the fourth resistor R4 is connected to the other end of the first capacitor C1 and grounded; the operating voltage generated by the power supply circuit 3 is input from one end of the fifth resistor R5, and the other end of the fifth resistor R5 It is connected to the cathode of the three-terminal adjustable shunt reference source T1 and serves as the output end of the zero-crossing pulse signal SI, and the anode of the three-terminal adjustable shunt reference source T1 is grounded.

The first stage of the power supply circuit 3 can provide 15V or 12V DC operating voltage to the drive circuit 6, and the second stage is 5V or 3.3V DC operating voltage, which is provided to the sampling circuit 4 and the MCU circuit. The power supply circuit 3 It can be done using existing technology.

The working method of the drive circuit 6 can be found in the Chinese invention patent, the name of the invention: undervoltage/shunt release circuit, the application number 02138669.2 invention patent application publication.

The working method of the above-mentioned AC shunt release includes:

① When the button switch K connected in parallel to the AC intermediate relay 7 is turned on, the AC input voltage ui is directly added to the AC input terminal of the rectifier circuit 1 in the AC shunt release 8, and the rectifier circuit 1 generates a one-way The pulsating DC voltage Ui; the unidirectional pulsating DC voltage Ui is sent to one end of the strong load circuit 2, the sampling circuit 4 and the shunt electromagnet coil 7; the sampling circuit 4 carries out the unidirectional pulsating DC voltage Ui After sampling, the MCU circuit 5 is made to obtain the sampling voltage Vsa and the zero-crossing pulse signal SI collected by the sampling circuit 4; the MCU circuit 5 judges the unidirectional pulsating direct current according to the sampling voltage Vsa and the zero-crossing pulse signal SI Whether the voltage Ui reaches 60% of the rated voltage value Ue of the shunt electromagnet coil work; if it reaches, the MCU circuit 5 outputs a control signal to cut off the strong load circuit 2, so that the unidirectional pulsating DC The voltage value of the voltage Ui rises rapidly, and the MCU circuit 5 generates a single pulse signal lasting 50-60 ms when the unidirectional pulsating DC voltage Ui crosses zero, and the single pulse signal is amplified by the driving circuit 6, Controlling the electrical conduction of the shunt electromagnet coil 9, so that the armature in the AC shunt release 8 works to realize the opening action;

② When the button switch K is released, the coil of the AC intermediate relay 7 obtains a voltage above 90% of the AC input voltage ui; the MCU circuit 5 according to the sampling voltage Vsa and the zero-crossing pulse signal SI Judging whether the unidirectional pulsating DC voltage Ui is lower than 50% of the rated voltage value Ue of the shunt electromagnet coil 9; if lower, the MCU circuit 5 controls the access of the strong load circuit 2, The unidirectional pulsating DC voltage Ui is quickly pulled down to below 10% of the rated voltage value Ue; and the MCU circuit 5 does not generate the single pulse signal, then the shunt electromagnet coil 9 does not conduct Pass.

Apparently, the above-mentioned embodiments are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And these obvious changes or modifications derived from the spirit of the present invention are still within the protection scope of the present invention. the

Claims (1)

1. A method for working in series with an AC shunt release and an AC relay, characterized in that it comprises: ①When the button switch (K) connected in parallel to the AC intermediate relay (7) is turned on, the AC input voltage (ui) is directly applied to the AC connection of the rectifier circuit (1) in the AC shunt release (8). At the input end, the rectifier circuit (1) generates a unidirectional pulsating DC voltage (Ui); the unidirectional pulsating DC voltage (Ui) is sent to the strong load circuit (2), sampling circuit (4) and shunt electromagnet One end of the coil (7); after the sampling circuit (4) samples the unidirectional pulsating DC voltage (Ui), the MCU circuit (5) obtains the sampling voltage Vsa and Zero-crossing pulse signal SI; the MCU circuit (5) judges whether the unidirectional pulsating DC voltage (Ui) reaches the rated voltage value of the shunt electromagnet coil according to the sampling voltage Vsa and zero-crossing pulse signal SI 60% of Ue; if reached, the MCU circuit (5) outputs a control signal to cut off the heavy load circuit (2), so that the voltage value of the unidirectional pulsating DC voltage (Ui) rises rapidly, and the The MCU circuit (5) generates a single pulse signal lasting 50-60 ms when the unidirectional pulsating DC voltage (Ui) crosses zero, and the single pulse signal is amplified by the drive circuit (6) to control the splitter The excitation electromagnet coil (9) is electrically conducted, so that the armature in the AC shunt release (8) works to realize the opening action; ② When the button switch (K) is released, the coil of the AC intermediate relay (7) obtains a voltage above 90% of the AC input voltage (ui); the MCU circuit (5) according to the sampling The voltage Vsa and the zero-crossing pulse signal SI judge whether the unidirectional pulsating DC voltage (Ui) is lower than 50% of the rated voltage value Ue of the shunt electromagnet coil (9); if lower, the MCU The circuit (5) controls the connection of the strong load circuit (2), so that the unidirectional pulsating DC voltage (Ui) is quickly pulled down to below 10% of the rated voltage value Ue; and the MCU circuit (5) If the single-shot pulse signal is not generated, the shunt electromagnet coil (9) is not conducted.

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