A device with autonomous matching mode against power surge

Abstract

The application relates to a defense fluctuation type device with an autonomous matching mode, which comprises an AC LN power supply, an AC / DC rectifier circuit, an operation controller circuit, a sampling circuit, a driving circuit, a 6-way electronic switch and an output port; the defense fluctuation type device is also provided with the autonomous matching mode, when the contactor is in a closed state, impedance matching calculation, current matching calculation, voltage matching calculation, autonomous identification verification and normal operation matching are automatically executed in sequence, according to the positive half cycle or the negative half cycle of the fluctuation voltage, the corresponding switch of the 6-way electronic switch is controlled to be opened and closed, and the output voltage of the AC / DC rectifier circuit is controlled according to the K value of the autonomous identification verification; the stability, the effectiveness and the applicability of the anti-fluctuation device are improved, the current direction through the contactor coil cannot be immediately reversed, the contactor cannot be tripped when fluctuation occurs in different half cycles, and the application effectiveness is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of power system, and particularly relates to a device for preventing power swing with self-matching mode. BACKGROUND

[0002] A large number of contactors are widely used in industrial enterprise power supply and distribution system to control various types of motor control, production process control, valve control, etc. However, the applicant found that once the power supply and distribution system is subjected to power swing, various production processes will be stopped, causing a large amount of economic loss, and even more, causing casualties of people who are working on the moving equipment. Especially in batch process control, once power swing occurs, thousands of devices will be stopped, and it usually takes several hours or even several days to restart the process. Therefore, it is of great practical significance to ensure that various contactors do not stop running and realize continuous operation when power swing occurs.

[0003] Moreover, when the existing AC power source is used to switch the DC capacitor, the automatic identification function is missing, which cannot ensure that it is applicable to all types of AC contactors, and at the same time, the randomness affects that power swing may occur in the positive half cycle of voltage or in the negative half cycle of voltage. If it occurs in the negative half cycle, if the direction of the DC voltage is not updated synchronously, it may cause the contactor to be unable to keep from tripping, losing the effect of resisting power swing. SUMMARY

[0004] To solve the above problems in the prior art, the present application provides a device for preventing power swing with self-matching mode.

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] The present invention discloses a device for preventing power surges with an autonomous matching mode, comprising an AC LN power supply, an AC / DC rectifier circuit, an operation controller circuit, a sampling circuit, a drive circuit, a 6-way electronic switch, and an output port. The L and N poles of the AC LN power supply are connected to the AC end of the AC / DC rectifier circuit, the operation controller circuit, and two of the 6-way electronic switches. The sampling circuit is connected to the operation controller circuit and the L and N poles of the AC LN power supply, and collects the current I1 of the LN circuit and the output current I2 of the AC / DC rectifier circuit. The drive circuit is connected to the 6-way electronic switch. The switch is connected to the operation controller circuit, and the output port is connected to the coil of the contactor in the power supply and distribution system; the anti-swing device is also provided with an autonomous matching mode. In the autonomous matching mode, when the contactor is in the closed state, it automatically executes the autonomous matching control method including impedance matching calculation, current matching calculation, voltage matching calculation, autonomous identification verification, and normal operation matching in sequence, and controls the opening and closing of the corresponding switches of the 6-way electronic switches according to the positive half cycle or negative half cycle of the voltage, and calculates and controls the output voltage of the AC / DC rectifier circuit with the K value that is autonomously identified and verified.

[0007] Furthermore, the 6-way electronic switch includes switches K1 to K6, the L pole and N pole of the AC LN power supply are connected to switch K1 and switch K2 respectively, the positive output end of the AC / DC rectifier circuit is connected to switch K3 and switch K6, and the negative output end is connected to switch K4 and switch K5, the other end of switch K3 is connected in parallel with switch K1, the other end of switch K4 is connected in parallel with switch K2, the other end of switch K5 is connected in parallel with switch K1, and the other end of switch K6 is connected in parallel with switch K2.

[0008] Furthermore, the autonomous matching control method includes:

[0009] S1. Impedance matching calculation: Collect the line voltage U of the L and N poles of the AC LN power supply and the current I1 flowing through the switch K1 and switch K2 loop, according to the formula The matching impedance Z is obtained, then the equivalent resistance Where R is the equivalent resistance, X is the equivalent reactance, and φ is the equivalent impedance angle;

[0010] S2. Current matching calculation: Based on the current I1 collected by S1, calculate the RMS value I of I1 1_rms , as the matching current;

[0011] S3. Voltage matching calculation: Matching impedance R and matching current I calculated based on S1 and S2 1_rms The output voltage Udc of the AC / DC rectifier circuit controlled by the operation controller circuit is Udc=k*I 1_rms *R, where k = 0.5;

[0012] S4. Self-identifying check: detecting the line voltage U sampled by S1, and according to the voltage positive half cycle or voltage negative half cycle, the corresponding switch of the 6-way electronic switch is controlled to open and close, and the output current I2 of the AC / DC rectifier circuit is detected and judged to obtain the K value of the self-identifying check;

[0013] S5. Normal operation matching: after S1-S4 is executed, the device enters the normal operation mode, when the voltage fluctuation occurs, the switch K1 and the switch K2 are opened, if the voltage fluctuation occurs in the positive half cycle of the voltage, the switch K3 and the switch K4 are closed, if the voltage fluctuation occurs in the negative half cycle of the voltage, the switch K5 and the switch K6 are closed, and the K value obtained by S4 is used to calculate and output the output voltage Udc of the AC / DC rectifier circuit.

[0014] Further, the self-identifying check of S4 includes:

[0015] S4-1. Detecting the line voltage U sampled by S1, when the voltage fluctuation occurs in the positive half cycle of the voltage, the switch K1 and the switch K2 are opened, and the switch K3 and the switch K4 are immediately closed, then the output current I2 of the AC / DC rectifier circuit is detected, if |I2|>0.4I 1_rms , the K value is stored as the default value, otherwise k=k+0.1; then the switch K3 and the switch K4 are opened, and the switch K1 and the switch K2 are closed, then the switch K1 and the switch K2 are opened again, and the switch K3 and the switch K4 are immediately closed, the output current I2 of the AC / DC rectifier circuit is detected again and the |I2|>0.4I 1_rms is judged, and the cycle is repeated until I2|>0.4I 1_rms .

[0016] S4-2. Detecting the line voltage U sampled by S1, when the voltage fluctuation occurs in the negative half cycle of the voltage, the switch K1 and the switch K2 are opened, and the switch K5 and the switch K6 are immediately closed, then the output current I2 of the AC / DC rectifier circuit is detected, if |I2|>0.4I 1_rms , the K value is stored as the default value; otherwise k=k+0.1; then the switch K5 and the switch K6 are opened, and the switch K1 and the switch K2 are closed, then the switch K1 and the switch K2 are opened again, and the switch K5 and the switch K6 are immediately closed, the output current I2 of the AC / DC rectifier circuit is detected again and the |I2|>0.4I 1_rms is judged, and the cycle is repeated until I2|>0.4I 1_rms .

[0017] The beneficial effects of the present application are:

[0018] (1) the contactor coil impedance matching is carried out, the current corresponding to the direct current resistance is guaranteed when switching from alternating current to direct current, and the effective range in use is determined by using the k value, which greatly improves the stability, effectiveness and applicability of the anti-swing power device;

[0019] (2) the randomness of voltage when the swing power occurs in the positive half cycle or the negative half cycle is met, the direct current voltage of different polarities is connected in the respective half cycle, so that the direction of the current flowing through the contactor coil does not immediately reverse, thereby ensuring that the contactor does not trip when the swing power occurs in different half cycles, and the effectiveness of the application is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the circuit structure schematic diagram of the anti-swing power device with self-matching mode according to the application;

[0021] Figure 2 is the flowchart of the self-matching control method in the anti-swing power device with self-matching mode according to the application. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the application clearer, the application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application and not to limit the application.

[0023] As shown in Figure 1 , the anti-swing power device with self-matching mode according to the application comprises an alternating current LN power supply 1, an AC / DC rectifier circuit 2, an operation controller circuit 3, a sampling circuit 4, a driving circuit 5, a 6-way electronic switch 6 and an output port 7. The L pole and the N pole of the alternating current LN power supply 1 are connected with the AC end of the AC / DC rectifier circuit 2, the operation controller circuit 3 and 2-way switches in the 6-way electronic switch 6. The sampling circuit 4 is connected with the operation controller circuit 3, the L pole and the N pole of the alternating current LN power supply 1, and collects the current I1 of the LN loop and the output current I2 of the AC / DC rectifier circuit 2. The driving circuit 5 is connected with the 6-way electronic switch 6 and the operation controller circuit 3. The output port 7 is connected with the coil of the contactor 8 in the power supply and distribution system. The anti-swing power device is also provided with a self-matching mode. When the contactor is in a closed state, the self-matching control method including impedance matching calculation, current matching calculation, voltage matching calculation, self-identification verification and normal operation matching is automatically executed. According to the swing power in the positive half cycle or the negative half cycle of the voltage, the corresponding switches of the 6-way electronic switch 6 are controlled to be opened and closed, and the output voltage of the AC / DC rectifier circuit 2 is controlled by the K value calculation of the self-identification verification.

[0024] The sampling circuit 4 may use a current sensor or a series loop circuit to collect the voltage generated by the current flowing through the resistor. The six-way electronic switch 6 includes switches K1 to K6. The L pole and N pole of the AC LN power supply 1 are connected to switch K1 and switch K2, respectively. The positive output end of the AC / DC rectifier circuit 2 is connected to switches K3 and K6, and the negative output end is connected to switches K4 and K5. The other end of switch K3 is connected in parallel with switch K1, the other end of switch K4 is connected in parallel with switch K2, the other end of switch K5 is connected in parallel with switch K1, and the other end of switch K6 is connected in parallel with switch K2.

[0025] like Figure 2 As shown, the autonomous matching control method of the present invention includes:

[0026] Step S1. Impedance matching calculation: Collect the line voltage U of the L and N poles of the AC LN power supply 1 and the current I1 flowing through the switch K1 and switch K2 loop, according to the formula The matching impedance Z is obtained, then the equivalent resistance Where R is the equivalent resistance, X is the equivalent reactance, and φ is the equivalent impedance angle.

[0027] Step S2. Current matching calculation: Based on the current I1 collected in step S1, calculate the RMS value I of I1 1_rms , as the matching current.

[0028] Step S3. Voltage matching calculation: The matching impedance R and matching current I calculated according to steps S1 and S2 are 1_rms The operation controller circuit 3 controls the output voltage Udc of the AC / DC rectifier circuit 2 to be Udc=k*I 1_rms *R, where k = 0.5;

[0029] Step S4. Autonomous Identification Verification: Detect the line voltage U sampled in step S1, and control the opening and closing of the corresponding switches of the six electronic switches 6 during the positive or negative half-cycle of the voltage according to the power fluctuation. Detect and determine the output current I2 of the AC / DC rectifier circuit 2 to obtain the K value for autonomous identification verification. Specifically, the following steps are included:

[0030] S4-1. Detect the line voltage U sampled in step S1. When the power is in the positive half cycle of the voltage, disconnect switches K1 and K2, and immediately close switches K3 and K4. Then detect the output current I2 of the AC / DC rectifier circuit 2. If |I2|>0.4I 1_rmsIf |I2| > 0.4I, then store k value as default value, otherwise let k = k + 0.1; then open switch K3 and switch K4, and close switch K1 and switch K2, then reopen switch K1 and switch K2, and immediately close switch K3 and switch K4, again detect output current I2 of AC / DC rectifier circuit 2 and perform |I2| > 0.4I 1_rms determination, and repeat the cycle until |I2| > 0.4I 1_rms .

[0031] S4-2. Detect the line voltage U sampled in step S1, when the voltage is in the negative half cycle, open switch K1 and switch K2, and immediately close switch K5 and switch K6, then detect output current I2 of AC / DC rectifier circuit 2, if |I2| > 0.4I 1_rms then store k value as default value; otherwise let k = k + 0.1; then open switch K5 and switch K6, and close switch K1 and switch K2, then reopen switch K1 and switch K2, and immediately close switch K5 and switch K6, again detect output current I2 of AC / DC rectifier circuit 2 and perform |I2| > 0.4I 1_rms determination, and repeat the cycle until |I2| > 0.4I 1_rms .

[0032] Because k starts from 0.5, the theory should be |I2| ≥ 0.5I 1_rms , but in order to avoid measurement error, so determine |I2| > 0.4I 1_rms , this value is just to limit the AC / DC rectifier module to the contactor power supply, can maintain the contactor not tripping current, determine greater than 0 can be, |I2| > 0.4I 1_rms can effectively avoid measurement error.

[0033] Step S5. Normal operation matching: after the completion of steps S1-S4, the device enters normal operation mode, when the voltage is in the positive half cycle, open switch K1 and switch K2, if the voltage is in the negative half cycle, close switch K5 and switch K6, and calculate the k value obtained in S4, output control AC / DC rectifier circuit 2 output voltage Udc.

[0034] It can be seen that the anti-flicker device of the application can match the impedance of the contactor coil, ensure the current corresponding to the direct current resistance when switching from alternating current to direct current, maintain the current, determine the effective range in use by the k value, greatly improve the stability, effectiveness and applicability of the anti-flicker device, meet the randomness of flicker when the voltage occurs in the positive half cycle or the negative half cycle, ensure that the direct current voltage of different polarities is connected in the respective half cycle, thereby ensuring that the current direction through the contactor coil does not immediately reverse, thereby ensuring that the contactor does not trip when flicker occurs in different half cycles, and greatly improving the effectiveness of the application.

[0035] Therefore, the anti-flicker device of the application can adapt to multiple types of alternating current contactors, automatically adapt to the impedance characteristics of the contactor, greatly improve the applicability and practicality of the anti-flicker device, and can significantly reduce the on-site debugging time and improve the flexibility of the application.

[0036] The above is the preferred embodiment of the application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the application, and these improvements and refinements are also considered within the protection scope of the application.

Claims

1. A device against power surge with autonomous matching mode, characterized by, The device for preventing fluctuation of power supply includes an AC LN power supply, an AC / DC rectifier circuit, an operation controller circuit, a sampling circuit, a driving circuit, a 6-way electronic switch and an output port, the L pole and the N pole of the AC LN power supply are connected with the AC end of the AC / DC rectifier circuit, the operation controller circuit and 2-way switches in the 6-way electronic switch, the sampling circuit is connected with the operation controller circuit, the L pole and the N pole of the AC LN power supply and collects the current I1 of the LN loop and the output current I2 of the AC / DC rectifier circuit, the driving circuit is connected with the 6-way electronic switch and the operation controller circuit, and the output port is connected with the coil of the contactor in the power supply system; the device for preventing fluctuation of power supply is also provided with an autonomous matching mode, when the contactor is in the closed state, the autonomous matching control method including impedance matching calculation, current matching calculation, voltage matching calculation, autonomous identification verification and normal operation matching is automatically executed, the corresponding switches of the 6-way electronic switch are controlled to be opened and closed according to the fluctuation of power supply in the positive half cycle or the negative half cycle of voltage, and the output voltage of the AC / DC rectifier circuit is controlled according to the K value of the autonomous identification verification; The autonomous matching control method includes: S1. Impedance matching calculation: collect the line voltage U of L and N poles of AC LN power supply and the current I1 flowing through the loop of switch K1 and switch K2, and get the matching impedance Z according to the formula , then the equivalent resistance , where R is the equivalent resistance, X is the equivalent reactance, is the equivalent impedance angle; S2. Current matching calculation: Based on the current I1 collected by S1, calculate the RMS value I of I1 1_rms , as the matching current; S3. Voltage matching calculation: The equivalent resistance R and the matching current I calculated from S1 and S2 1_rms The operation controller circuit controls the output voltage Udc of the AC / DC rectifier circuit to Udc = k * I 1_rms *R, where k＝0.5； S4. Autonomous identification verification: detecting the line voltage U sampled in S1, and controlling the corresponding switches of the 6-way electronic switch to be opened and closed according to the fluctuation of power supply in the positive half cycle or the negative half cycle of voltage, and detecting and judging the output current I2 of the AC / DC rectifier circuit to obtain the K value of the autonomous identification verification; S5. Normal operation matching: after the execution of S1-S4, the device enters the normal operation mode, when the fluctuation of power supply occurs, the switches K1 and K2 are opened, if the fluctuation of power supply occurs in the positive half cycle of voltage, the switches K3 and K4 are closed, if the fluctuation of power supply occurs in the negative half cycle of voltage, the switches K5 and K6 are closed, and the output voltage Udc of the AC / DC rectifier circuit is calculated and output according to the K value obtained in S4.

2. The apparatus of claim 1, wherein, The 6-way electronic switch includes switches K1-K6, the L pole and the N pole of the AC LN power supply are connected with the switches K1 and K2 respectively, the positive output end of the AC / DC rectifier circuit is connected with the switches K3 and K6, the negative output end is connected with the switches K4 and K5, the other end of the switch K3 is connected with the switch K1 in parallel, the other end of the switch K4 is connected with the switch K2 in parallel, the other end of the switch K5 is connected with the switch K1 in parallel, and the other end of the switch K6 is connected with the switch K2 in parallel.

3. The apparatus of claim 2, wherein, The autonomous identification verification of S4 includes: S4-1. Detect the line voltage U of S1 sampling, when the voltage is in the positive half cycle, open switch K1 and switch K2, and immediately close switch K3 and switch K4, then detect the output current I2 of the AC / DC rectifier circuit, if |I2|>0.4I 1_rms , then store the k value as the default value; otherwise let k=k+0.1; then open switch K3 and switch K4, and close switch K1 and switch K2, then reopen switch K1 and switch K2, and immediately close switch K3 and switch K4, again detect the output current I2 of the AC / DC rectifier circuit and judge |I2|>0.4I 1_rms , then store the k value as the default value; otherwise let k=k+0.1; then open switch K3 and switch K4, and close switch K1 and switch K2, then reopen switch K1 and switch K2, and immediately close switch K3 and switch K4, again detect the output current I2 of the AC / DC rectifier circuit and judge |I2|>0.4I 1_rms , then store the k value as the default value; otherwise let k=k+0.1; then open switch K3 and switch K4, and close switch K1 and switch K2, then reopen switch K1 and switch K2, and immediately close switch K3 and switch K4, again detect the output current I2 of the AC / DC rectifier circuit and judge |I2|>0.4I S4-2. Detect the line voltage U of S1 sampling, when the voltage negative half cycle, open switch K1 and switch K2, and immediately close switch K5 and switch K6, then detect the output current I2 of AC / DC rectifier circuit, if |I2|>0.4I 1_rms , then store k value as default value; otherwise let k=k+0.1; then open switch K5 and switch K6, and close switch K1 and switch K2, then reopen switch K1 and switch K2, and immediately close switch K5 and switch K6, again detect the output current I2 of AC / DC rectifier circuit and carry out |I2|>0.4I 1_rms , then store k value as default value; otherwise let k=k+0.1; then open switch K5 and switch K6, and close switch K1 and switch K2, then reopen switch K1 and switch K2, and immediately close switch K5 and switch K6, again detect the output current I2 of AC / DC rectifier circuit and carry out |I2|>0.4I 1_rms , then store k value as default value; otherwise let k=k+0.1; then open switch K5 and switch K6, and close switch K1 and switch K2, then reopen switch K1 and switch K2, and immediately close switch K5 and switch K6, again detect the output current I2 of AC / DC rectifier circuit and carry out |I2|>0.4I

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