Adjusting system based on plant distribution undervoltage

Abstract

The invention relates to the technical field of under-voltage power distribution, in particular to a regulating system based on plant distribution under-voltage, which comprises a voltage detection loop, a power electricity switching loop, a boosting loop and a controller, wherein the voltage detection loop is used for collecting a three-phase voltage value; the controller receives the three-phase voltage value and outputs an undervoltage or normal voltage state signal; the power electricity switching loop switches the normal loop or the boost loop according to the state signal; the boost loop boosts the input under-voltage value and outputs a boosted voltage value; the controller adjusts the duty ratio of the first phase shifter according to the received boosted voltage value, so that the boosted voltage value reaches a normal voltage value. The invention solves the problems of large occupied space and limited planning installation position when a transformer is used for boosting in an existing factory.

Description

Technical Field

[0001] The present invention relates to the technical field of undervoltage power distribution, and in particular to a regulation system based on factory-distributed undervoltage. Background Art

[0002] The power of the equipment used in the factory is different. When multiple high-power equipment are started at the same time or reach the peak at the same time, the equipment in the factory will encounter a sudden voltage drop. This phenomenon often causes most components to stop working due to undervoltage, causing sudden equipment shutdown, collision, blockage, etc., seriously affecting the normal flow of the production line in the factory.

[0003] The traditional solution is to add a voltage stabilizer next to the equipment, but the voltage stabilizer is bulky and requires additional planning for the installation location. The circuit designed this time does not use a transformer, which greatly reduces the installation space while also achieving a voltage boost. Summary of the invention

[0004] Aiming at the deficiencies of the existing circuits, the present invention solves the problem that the existing factory area uses transformers for voltage boosting, which occupies a large space and has limited planning and installation locations.

[0005] The technical solution adopted by the present invention is: a regulation system based on factory-matched undervoltage includes:

[0006] Voltage detection circuit, power switching circuit, boost circuit and controller; among them,

[0007] The voltage detection circuit is used to collect the voltage value of three-phase electricity;

[0008] The controller receives the voltage value of the three-phase electricity and outputs the status signal of undervoltage or normal voltage;

[0009] The power electric switching circuit switches to a normal circuit or a boost circuit according to the status signal;

[0010] The boost circuit boosts the input undervoltage value and outputs the boosted voltage value;

[0011] The controller adjusts the duty cycle of the first phase shifter according to the received boosted voltage value so that the boosted voltage value reaches a normal voltage value.

[0012] As a preferred implementation of the present invention, the voltage detection circuit includes: a voltage detector UT1 and a voltage detection relay KA1, and UT1 is electrically connected to KA1.

[0013] As a preferred embodiment of the present invention, the power electrical switching circuit includes: a normally closed contact of KA1, a normal switching contactor KM1, and an undervoltage switching contactor KM2. The upper end of KM1 is connected to the normally closed contact of KA1, the upper end of KM2 is connected to the normally open contact of KA1, and the upper end of the normally closed contact of KA1 is connected to the contacts of KM1 and KM2.

[0014] As a preferred embodiment of the present invention, the upper end of the boost circuit is connected to the lower end of the normally open contact of KM2, and the lower end of the boost circuit is connected to the lower end of the normally open contact of KM1.

[0015] As a preferred embodiment of the present invention, the number of boost circuits is 3.

[0016] As a preferred embodiment of the present invention, the boost circuit includes: a rectifier circuit, a chopper circuit, an inverter circuit and a voltage feedback circuit, and the rectifier circuit is electrically connected to the chopper circuit, the inverter circuit and the voltage feedback circuit in sequence.

[0017] As a preferred embodiment of the present invention, the rectifier circuit includes: an uncontrolled rectifier bridge BD1, an inductor L3 and a capacitor Ci3, the output positive end of BD1 is connected to the left end of L3, the right end of L3 is connected to the upper end of Ci3, and the lower end of Ci3 is connected to the output negative end of BD1.

[0018] As a preferred embodiment of the present invention, the chopper circuit includes: inductors L1, L2, capacitors Ci1, Ci2, C1, IGBT tubes S1, S2, S3, S4, phase shifter U1, resistors R1, R2 and Rs, Ci1 and Ci2 are connected in parallel and connected to both ends of Ci3, the common upper ends of Ci1 and Ci2 are connected to the left ends of L1 and L2 respectively, the right end of L1 is connected to the left end of R1, the right end of L2 is connected to the left end of R2, and the right end of R1 is connected to the left end of R2. The emitter collector of S4 and the collector of S2 are connected, the right end of R2 is connected to the emitter of S3 and the collector of S1 respectively, the common emitter of S1 and S2 is connected to the common lower end of Ci1 and Ci2, the upper end of Rs and C1 in series is connected to the common collector of S3 and S4, and the lower end of Rs and C1 in series is connected to the common emitter of S1 and S2; the gates of S1 and S4 are connected to one end of the output of U1, and the gates of S2 and S3 are connected to the other end of the output of U1.

[0019] As a preferred embodiment of the present invention, the inverter circuit includes: IGBT tubes S5, S6, S7, S8, a phase shifter U2, a resistor R, an inductor L and a capacitor C, the emitter of S5 is connected to the collector of S7, the emitter of S6 is connected to the collector of S8, the common collector of S5 and S6 is connected to the common collector of S3 and S4; the common emitter of S7 and S8 is connected to the common emitter of S1 and S2; the gates of S7 and S6 are connected to one output end of U2, and the gates of S5 and S8 are connected to the other output end of U2.

[0020] As a preferred embodiment of the present invention, the controller includes: a PLC controller.

[0021] Beneficial effects of the present invention:

[0022] 1. The present invention detects the input voltage of the three-phase electricity in real time through a voltage detection circuit, and uses a controller to judge the detected voltage, thereby switching the normal circuit or the boost circuit;

[0023] 2. Detect the output voltage of the boost circuit to determine whether it is a normal voltage value. By adjusting the duty cycle of the phase shifter, adjust the output voltage of the boost circuit to make the output voltage reach the normal voltage value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of the regulation system based on factory-matched undervoltage of the present invention;

[0025] Figure 2 It is a schematic diagram of the system workflow;

[0026] Figure 3 It is a circuit diagram of the factory-equipped undervoltage regulation system of the present invention;

[0027] Figure 4 is a boost circuit diagram of the present invention;

[0028] Figure 5 It is the input and output waveform diagram of the boost circuit of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the accompanying drawings and embodiments. This figure is a simplified schematic diagram, which only illustrates the basic structure of the present invention in a schematic manner, and therefore it only shows the components related to the present invention.

[0030] like Figure 1 and 2 As shown, a regulation system based on factory-equipped undervoltage includes: a voltage detection circuit, a power electric switching circuit, a boost circuit and a controller, wherein the voltage detection circuit, the power electric switching circuit and the boost circuit are electrically connected; the voltage detection circuit, the boost circuit and the controller; wherein,

[0031] The voltage detection circuit is used to collect three-phase voltage values;

[0032] The controller receives the three-phase voltage value and outputs a status signal of undervoltage or normal voltage;

[0033] The power electric switching circuit switches to a normal circuit or a boost circuit according to the status signal;

[0034] The boost circuit boosts the input undervoltage value and outputs the boosted voltage value;

[0035] The controller adjusts the duty cycle of the first phase shifter according to the received boosted voltage value so that the boosted voltage value reaches a normal voltage value; Figure 1 The dashed line in the middle is the signal flow of the controller, and the solid line is the electrical signal.

[0036] like Figure 3 The voltage detection circuit detects the voltage of the three-phase electricity L1 to L3. The normal voltage value of each phase of the three-phase electricity is 220V. The voltage detection circuit sends the detection voltage to the controller. The controller determines whether the detection voltage is normal voltage, thereby actuating the voltage detection relay, normal switching contactor and undervoltage switching contactor, and selecting the normal circuit or the boost circuit.

[0037] When the voltage detector UT1 of the voltage detection circuit does not receive the undervoltage signal alarm, UT1 does not trigger the voltage detection relay KA1, the normally closed contact of KA1 is turned on, and the equipment is powered by the main circuit controlled by the normal switching contactor KM1; when UT1 detects the undervoltage alarm, the controller triggers the instruction to close the normally open point of KA1 and the undervoltage switching contactor KM2 coil (AC contactor) is closed, then the normally open contact of KM2 is closed and turned on, and the normally open contact of KM1 is disconnected; the first to third boost circuits TT1-TT3 are used for voltage compensation to deliver the required amplitude of electrical energy to the equipment for power supply.

[0038] The power switching circuit is mainly composed of KM1 and KM2. A certain branch is selected to be turned on through the status signal detected by the controller; if the KM1 branch is turned on, the subsequent stage directly supplies power to the equipment; otherwise, the KM2 branch is turned on, indicating that the circuit is in an undervoltage state, and the subsequent stage needs to pass through the boost circuit to compensate the voltage before output; the boost circuit is mainly composed of three single-phase boost circuits; any boost circuit is composed of a set of AC-DC-AC circuits, in which the main DC-DC circuit that plays a boosting role is designed; the voltage value measured by the voltage detection circuit is fed back to the controller, and the controller can use a PLC controller; the controller uses PWM modulation according to the size of the required compensation value to control the duty cycle of the phase shift controller in the DC-DC circuit, thereby compensating the voltage output and achieving the boost effect.

[0039] like Figure 4It is a boost circuit, which is composed of three single-phase boost circuits. This ensures that when one circuit fails, the other two circuits can still operate normally.

[0040] Taking a boost circuit as an example, the boost circuit mainly includes: rectification circuit, chopper circuit, inverter circuit and voltage feedback circuit;

[0041] The rectifier circuit is composed of an uncontrolled rectifier bridge BD1 and an LC filter circuit to convert sinusoidal AC into stable DC;

[0042] The rectifier circuit includes: BD1, inductor L3 and capacitor Ci3. The input end of BD1 is connected to 220V AC, the positive output end of BD1 is connected to the left end of L3, the right end of L3 is connected to the upper end of Ci3, the lower end of Ci3 is connected to the negative output end of BD1 and is grounded.

[0043] The chopper circuit is a BOOST boost topology structure. Through the interactive operation of the two circuits, the BOOST circuit adopts IGBT tubes to reduce the stress and loss of components. The signal of the phase-shift controller U1 is used to achieve: S1 and S4 are turned on at the same time or S2 and S3 are turned on at the same time, that is, when L1-R1-S2 is turned on, L2-R2-S3-RS-C1 is also turned on, and the two circuits are turned on and cut off at the same time; when L2-R2-S1 is turned on, L1-R1-S4-RS-C1 is also turned on, that is, the two circuits are turned on and cut off at the same time, and the voltage is increased through the interactive pumping effect of inductors L1 and L2.

[0044] The signal output of the phase shift controller U1 is based on the formula Where a represents the on-duty cycle, U 0 represents the output voltage, and E represents the input voltage; for example, if the undervoltage detected is 180V and the normal output voltage is 220V, then a=2 / 11.

[0045] The chopper circuit includes: inductors L1, L2, capacitors Ci1, Ci2, C1, IGBT tubes S1, S2, S3, S4, phase shifter U1 (first phase shifter), resistors R1, R2 and Rs. After Ci1 and Ci2 are connected in parallel, the two ends are connected in parallel with the two ends of Ci3. The common upper end of Ci1 and Ci2 is connected to the left ends of L1 and L2 respectively, the right end of L1 is connected to the left end of R1, the right end of L2 is connected to the left end of R2, and the right end of R1 is connected to the emitter collector of S4 and S3 respectively. The collector of R2 is connected, the right end of R2 is connected to the emitter of S3 and the collector of S1 respectively, the common emitter of S1 and S2 is connected to the common lower end of Ci1 and Ci2, the upper end of Rs and C1 connected in series is connected to the common collector of S3 and S4, and the lower end of Rs and C1 connected in series is connected to the common emitter of S1 and S2; the gates of S1 and S4 are connected to one end of the output of U1, and the gates of S2 and S3 are connected to the other end of the output of U1; the phase shifter U1 is electrically connected to the controller.

[0046] The inverter circuit adopts a full-bridge inverter circuit with an RLC series circuit to filter and output an AC square wave; the period of the AC square wave is output by adjusting the duty cycle of U2.

[0047] The inverter circuit includes: IGBT tubes S5, S6, S7, S8, and phase shifter U2 (second phase shifter); the emitter of S5 is connected to the collector of S7, the emitter of S6 is connected to the collector of S8, the common collector of S5 and S6 is connected to the common collector of S3 and S4; the common emitter of S7 and S8 is connected to the common emitter of S1 and S2, the gates of S7 and S6 are connected to one output end of U2, and the gates of S5 and S8 are connected to the other output end of U2.

[0048] The voltage feedback loop includes: a resistor R, an inductor L and a capacitor C, the upper end of R, L and C connected in series is connected to the common end of S5 and S7; the lower end of R, L and C connected in series is connected to the common end of S6 and S8.

[0049] Through the signal of the phase-shift controller U2, it is realized that: S5 and S8 are turned on at the same time or S6 and S7 are turned on at the same time, that is, when S5-RLC-S8 is turned on, S6-RLC-S7 is turned off; when S6-RLC-S7 is turned on, S5-RLC-S8 is turned off.

[0050] The voltage feedback loop is composed of RLC. The output voltage Vinv on the RLC side is sampled and fed back to the controller. The controller determines whether the current output voltage is normal, and then adjusts the duty cycle of the phase shift controller U1 of the chopper loop. A voltage feedback loop detection is added to the boost loop. The controller can adjust the boost loop voltage compensation value in real time according to the boost loop compensation voltage effect.

[0051] Working principle:

[0052] Figure 4 V1 is a 50HZ AC voltage Vac, and the process of converting AC to DC is realized through BD1, a single-phase bridge uncontrolled rectifier; BD1 is connected in series with inductor L3 and then in parallel with Ci3. L3 and Ci3 form an inductive-capacitive filter to suppress the impact of input current; the boost circuit uses two BOOST topologies to work interactively, and uses controllable IGBTs. Ci1 is connected in parallel with Ci2 and then connected in parallel with two interactive BOOST loops. The first boost loop is first connected to inductor L1, L1 The other end of L1 is connected to resistor R1, and then the other end of R1 is connected to the emitter of S4 and the collector of S2 at the same time. The collector of S4 is connected to the current limiting resistor Rs, and the other end of Rs is connected to the emitter of S2 after passing through the capacitor C1; the second boost loop is first connected to the inductor L2, the other end of L1 is connected to resistor R2, and then the other end of R2 is connected to the emitter of S3 and the collector of S1 at the same time. The collector of S3 is connected to the current limiting resistor Rs, and the other end of Rs is connected to the emitter of S1 after passing through the capacitor C1.

[0053] The inverter circuit is alternately turned on by two switches. The collector of the first switch S6 is connected to the output end of the chopper circuit, and the emitter is connected in series with RLC and then connected to the collector of S7; the collector of the other switch S5 is connected to the output end of the chopper circuit, and the emitter is connected in series with RLC and then connected to the collector of S8.

[0054] Among them, L3=500μH; Ci3=500μF; L1=470μF; L2=470μF; R1=20mΩ; R2=20mΩ; S1 to S8 models are FGL60N100BNTD; BD1 model is KBPC5010; Rs=25mΩ; C1=500μF; Ci1=500μF; Ci2=500μF; R=10Ω; L=1mH; C=1μF.

[0055] like Figure 5 This is the waveform after the boost circuit. The power supply after the boost circuit can be connected to the device, so that the boost power supply system can be used to power the device when the main circuit power supply system is undervoltage.

[0056] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A regulation system based on factory-provided undervoltage, characterized in that: include: Voltage detection circuit, power switching circuit, boost circuit and controller; among them, The voltage detection circuit is used to collect the voltage value of three-phase electricity; The controller receives the voltage value of the three-phase electricity and outputs the status signal of undervoltage or normal voltage; The power electric switching circuit switches to a normal circuit or a boost circuit according to the status signal; The boost circuit boosts the input undervoltage value and outputs the boosted voltage value; The controller adjusts the duty cycle of the first phase shifter according to the received boosted voltage value so that the boosted voltage value reaches a normal voltage value.

2. The regulation system based on factory-provided undervoltage according to claim 1 is characterized in that: The voltage detection circuit includes: a voltage detector UT1 and a voltage detection relay KA1, and UT1 is electrically connected to KA1.

3. The regulation system based on factory-provided undervoltage according to claim 2, characterized in that: The power electric switching circuit includes: the normally closed contact of KA1, the normal switching contactor KM1, and the undervoltage switching contactor KM2. The upper end of KM1 is connected to the normally closed contact of KA1, the upper end of KM2 is connected to the normally open contact of KA1, and the upper end of the normally closed contact of KA1 is connected to the contacts of KM1 and KM2.

4. The regulation system based on factory-provided undervoltage according to claim 3 is characterized in that: The upper end of the boost circuit is connected to the lower end of the normally open contact of KM2, and the lower end of the boost circuit is connected to the lower end of the normally open contact of KM1.

5. The regulation system based on factory-provided undervoltage according to claim 4, characterized in that: The boost circuit includes: a rectifier circuit, a chopper circuit, an inverter circuit and a voltage feedback circuit, and the rectifier circuit is electrically connected to the chopper circuit, the inverter circuit and the voltage feedback circuit in sequence.

6. The regulation system based on factory-provided undervoltage according to claim 5, characterized in that: The rectifier circuit includes: an uncontrolled rectifier bridge BD1, an inductor L3 and a capacitor Ci3, the output positive end of BD1 is connected to the left end of L3, the right end of L3 is connected to the upper end of Ci3, and the lower end of Ci3 is connected to the output negative end of BD1.

7. The regulation system based on factory-provided undervoltage according to claim 6, characterized in that: The chopper circuit includes: inductors L1, L2, capacitors Ci1, Ci2, C1, IGBT tubes S1, S2, S3, S4, phase shifter U1, resistors R1, R2 and Rs. Ci1 and Ci2 are connected in parallel and connected to both ends of Ci3. The common upper end of Ci1 and Ci2 is connected to the left ends of L1 and L2 respectively. The right end of L1 is connected to the left end of R1, the right end of L2 is connected to the left end of R2, and the right end of R1 is connected to the emitter of S4 respectively. The collector of Rs and S2 are connected, the right end of R2 is connected to the emitter of S3 and the collector of S1 respectively, the common emitter of S1 and S2 is connected to the common lower end of Ci1 and Ci2, the upper end of Rs and C1 in series is connected to the common collector of S3 and S4, and the lower end of Rs and C1 in series is connected to the common emitter of S1 and S2; the gates of S1 and S4 are connected to one end of the output of U1, and the gates of S2 and S3 are connected to the other end of the output of U1.

8. The regulation system based on factory-provided undervoltage according to claim 7, characterized in that: The inverter circuit includes: IGBT tubes S5, S6, S7, S8 and phase shifter U2, the emitter of S5 is connected to the collector of S7, the emitter of S6 is connected to the collector of S8, the common collector of S5 and S6 is connected to the common collector of S3 and S4; the common emitter of S7 and S8 is connected to the common emitter of S1 and S2; the gates of S7 and S6 are connected to one output end of U2, and the gates of S5 and S8 are connected to the other output end of U2.

9. The regulation system based on factory-provided undervoltage according to claim 1, characterized in that: The controller includes: PLC controller.

10. The regulation system based on factory-provided undervoltage according to claim 1, characterized in that: The number of boost circuits is 3.

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