Control circuit of reactive compensation controller and reactive compensation controller

Abstract

The utility model relates to a control circuit of a reactive compensation controller and the reactive compensation controller. The control circuit of the reactive compensation controller comprises a sampling circuit and a switch driving circuit. The sampling circuit comprises a voltage signal circuit, the voltage signal circuit comprises a voltage transformer, a filter and a voltage follower, the primary winding input end of the voltage transformer is suitable for being electrically connected with a power system circuit to be subjected to reactive compensation, and the secondary winding output end of the voltage transformer is electrically connected with the input end of the filter. The output end of the filter is electrically connected with the input end of the voltage follower; the output end of the voltage follower is electrically connected with the input end of the switch driving circuit, the switch driving circuit is suitable for generating and outputting a switching signal for controlling a switch of the reactive power compensation device according to a signal output by the sampling circuit, and the output end of the switch driving circuit is electrically connected with the switch of the reactive power compensation device. And the harm of harmonic pollution of a power system to the reactive compensation controller can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a control circuit of a reactive power compensation controller and a reactive power compensation controller. Background Art

[0002] With the rapid increase of nonlinear loads in the power supply system, the power grid has been increasingly affected by harmonic pollution and reactive power consumption. These nonlinear loads have greatly threatened the safe and economical operation of the power system and caused certain harm. At present, the main method is to connect the filter compensation branch to the power system, which usually includes a reactive compensation device and its switching elements, and use the reactive compensation controller and the trigger circuit of the switching element to control the switching of the filter compensation branch, so as to switch between the two states of connecting the reactive compensation device of the filter compensation branch to the power system to implement filtering and reactive compensation work and cutting out the power system to stop working.

[0003] Usually, the reactive power compensation controller is electrically connected to the power system circuit to be reactively compensated, collects its voltage signal in real time, obtains the compensation state of the power system according to the voltage signal of the power system, generates a switching signal according to the compensation state information fed back in real time, and controls the switching of the filter compensation branch. However, the harmonic pollution caused by the nonlinear load of the power system will cause harm to the circuit of the reactive power compensation controller. The sampling input end of the existing reactive power compensation controller is directly electrically connected to the power system, which is not conducive to the safe and economic operation of the reactive power compensation controller itself.

[0004] Therefore, how to reduce the harm of power system harmonic pollution to reactive power compensation controller has become an urgent problem to be solved by technical personnel in this field. Utility Model Content

[0005] In order to reduce the harm of harmonic pollution in the power system to the reactive power compensation controller, the present application provides a control circuit of the reactive power compensation controller and the reactive power compensation controller.

[0006] A control circuit of a reactive power compensation controller provided to achieve the purpose of the utility model comprises:

[0007] Sampling circuit and switch driving circuit;

[0008] The sampling circuit includes a voltage signal circuit, and the voltage signal circuit includes a voltage transformer, a filter and a voltage follower, wherein: the primary winding input end of the voltage transformer is suitable for being electrically connected to the power system circuit to be reactively compensated, the secondary winding output end of the voltage transformer is electrically connected to the input end of the filter, and the output end of the filter is electrically connected to the input end of the voltage follower;

[0009] The output end of the voltage follower is electrically connected to the input end of the switch drive circuit. The switch drive circuit is suitable for generating and outputting a switching signal for controlling the switch of the reactive compensation device according to the signal output by the sampling circuit. The output end of the switch drive circuit is suitable for being electrically connected to the switch of the reactive compensation device.

[0010] According to another aspect of the present application, a reactive power compensation controller is provided, and the reactive power compensation controller is provided with a control circuit of the reactive power compensation controller.

[0011] The present application adds a filter to the sampling circuit to reduce the impact of possible harmonic pollution in the power system on the switch drive circuit, the core component of the reactive power compensation controller, and can reduce the harm of harmonic pollution in the power system to the reactive power compensation controller. In addition, after the collected voltage signal is filtered by the filter, a voltage follower is added to separate the voltage signal to prevent excessive du / dt from affecting the stable operation of the switch drive circuit. In summary, compared with the control circuit of the existing reactive power compensation controller, the present application can reduce the harm of harmonic pollution in the power system to the reactive power compensation controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A circuit structure diagram showing a control circuit of a reactive power compensation controller according to an embodiment of the present application;

[0013] Figure 2 A circuit structure diagram showing a control circuit of a reactive power compensation controller according to an embodiment of the present application;

[0014] Figure 3 A schematic diagram showing the structure of a voltage signal circuit according to an embodiment of the present application is shown;

[0015] Figure 4 A schematic diagram showing the structure of a voltage signal circuit according to an embodiment of the present application is shown;

[0016] Figure 5 A connection structure diagram showing a voltage signal circuit and a switch driving circuit according to an embodiment of the present application;

[0017] Figure 6 A diagram showing a connection structure between a liquid crystal display module and a switch driving circuit according to an embodiment of the present application;

[0018] Figure 7 A diagram showing the connection structure between the clock chip and the switch driving circuit of an embodiment of the present application;

[0019] Figure 8 A structural diagram showing a reactive power compensation controller according to an embodiment of the present application;

[0020] Fig. 9 Show Figure 8Distribution diagram of the connection joints on the back side wall of the protective shell of the embodiment.

[0021] Sampling circuit 1000, voltage signal circuit 1100, voltage transformer 1110, voltage divider resistor R1, second resistor R2, filter 1120, voltage follower 1130, error amplifier 1131, fourth resistor R4, fifth resistor R5, current signal circuit 1200, switch drive circuit 2000, voltage regulator 3000, liquid crystal display module 4000, display screen 4100, operation button 4200, clock chip 5000, relay module 6000, protective shell 7000. DETAILED DESCRIPTION

[0022] Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0023] Among them, it should be understood that the directions or positional relationships indicated by terms such as "length", "width", "height", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention or simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0024] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.

[0025] The present application discloses a control circuit of a reactive power compensation controller, comprising a sampling circuit 1000 and a switch driving circuit 2000. The sampling circuit 1000 comprises a voltage signal circuit 1100, and the voltage signal circuit 1100 comprises a voltage transformer 1110, a filter 1120 and a voltage follower 1130, wherein: the primary winding input end of the voltage transformer 1110 is suitable for being electrically connected to a power system circuit to be reactively compensated, the secondary winding output end of the voltage transformer 1110 is electrically connected to the input end of the filter 1120 of the voltage signal circuit 1100, and the output end of the filter 1120 of the voltage signal circuit 1100 is electrically connected to the input end of its (the voltage signal circuit 1100) voltage follower 1130;

[0026] The output end of the voltage follower 1130 of the voltage signal circuit 1100 is electrically connected to the input end of the switch driving circuit 2000. The switch driving circuit 2000 is suitable for generating and outputting a switching signal for controlling the switch of the reactive compensation device according to the signal output by the sampling circuit 1000. The output end of the switch driving circuit 2000 is suitable for being electrically connected to the switch of the reactive compensation device.

[0027] Generally, the power load of the power system is an inductive load. After reactive compensation, the current of the main switch will decrease, not increase. At this time, overcompensation of reactive compensation in the power system will cause the total current to increase and the voltage to rise. Undercompensation of reactive compensation in the power system will also cause the total current to increase, and the voltage will decrease. The control circuit of the reactive compensation controller collects the voltage signal of the power system through the sampling circuit 1000. The switch drive circuit 2000 recognizes that the power system is in an overcompensation state according to the voltage signal, and then outputs a removal signal at the output end of the switch drive circuit 2000 to cut off the filter compensation branch from the power system, and stop filtering and reactive compensation. The switch drive recognizes that the power system is in an undercompensation state according to the voltage signal, and then outputs an input signal at the output end of the switch drive circuit 2000 to input the filter compensation branch into the power system for filtering and reactive compensation.

[0028] The present application adds a filter 1120 to the sampling circuit 1000 to reduce the impact of harmonic pollution that may exist in the power system on the switch drive circuit 2000, the core component of the reactive power compensation controller, and can reduce the harm of harmonic pollution in the power system to the reactive power compensation controller. In addition, after the collected voltage signal is filtered by the filter 1120, a voltage follower 1130 is added to separate the voltage signal to prevent excessive du / dt from affecting the stable operation of the switch drive circuit 2000. In summary, compared with the control circuit of the existing reactive power compensation controller, the present application can reduce the harm of harmonic pollution in the power system to the reactive power compensation controller.

[0029] In a possible implementation, the filter 1120 of the voltage signal circuit 1100 is a low-frequency filter 1120, and the input and output ends of the low-frequency filter 1120 are electrically connected to the output end of the voltage transformer 1110 and the input end of the voltage follower 1130, respectively. Figure 3 and Figure 4 .

[0030] In a possible implementation, the sampling circuit 1000 further includes a current signal circuit 1200, the input end of the current signal circuit 1200 is suitable for being electrically connected to the power system circuit to collect and detect its current signal, and the output end of the current signal circuit 1200 is electrically connected to the input end of the switch driving circuit 2000. The input end of the switch driving circuit 2000 generates and outputs a switching signal for controlling the switch of the reactive power compensation device according to the voltage and current signals collected by the sampling circuit 1000. Further, the current signal circuit 1200 includes a current transformer, a filter 1120 and a voltage follower 1130, the primary winding input end of the current transformer is suitable for being electrically connected to the power system circuit to be compensated, the output end of the current transformer is electrically connected to the input end of the filter 1120 of the current signal circuit 1200, the output end of the filter 1120 of the current signal circuit 1200 is electrically connected to the input end of its voltage follower 1130, and the output end of the voltage follower 1130 of the current signal circuit 1200 is electrically connected to the input end of the switch driving circuit 2000. The specific structures of the filter 1120 and the voltage follower 1130 of the current signal circuit 1200 refer to and are consistent with those of the voltage signal circuit 1100 .

[0031] In a possible implementation, the voltage signal circuit 1100 further includes a voltage regulator 3000, the positive electrode of the voltage regulator 3000 is grounded, and the negative electrode of the voltage regulator 3000 is electrically connected to the output end of the filter 1120. Furthermore, the switch drive circuit 2000 uses a TMS320F28335 chip. In order to prevent the overvoltage of the signal input to the DSP, a voltage regulator 3000 with a breakdown voltage of 3.3V is added after the low-pass filter circuit. When the voltage exceeds 3.3V, the voltage regulator 3000 breaks down, and the I / O port of the DSP will not be damaged due to overvoltage.

[0032] In a possible implementation, a voltage divider resistor R1 is connected to one side of the primary winding input end of the voltage transformer 1110 , and the input end of the primary winding is electrically connected to the power system circuit through the voltage divider resistor R1 .

[0033] In a possible implementation, the voltage signal circuit 1100 further includes a second resistor R2, such as Figure 3 As shown, the second resistor is electrically connected between the two ends of the secondary winding of the voltage transformer 1110, that is, the two ends of the secondary winding of the voltage transformer 1110 are electrically connected through the second resistor R2. One end of the second resistor R2 is grounded, and the other end of the second resistor R2 serves as the output end of the secondary winding and is electrically connected to the input end of the filter 1120.

[0034] In one possible implementation, the voltage follower 1130 includes an error amplifier 1131 and a fifth resistor R5, the output end of the filter 1120 is electrically connected to the positive input terminal of the error amplifier 1131, the fifth resistor R5 is electrically connected between the negative input terminal of the error amplifier 1131 and the output end of the error amplifier 1131, and the output end of the error amplifier 1131 is electrically connected to the input end of the switch drive circuit 2000.

[0035] In a possible implementation, the voltage follower 1130 further includes a fourth resistor R4 , which is electrically connected between the output end of the filter 1120 and the positive input terminal of the error amplifier 1131 .

[0036] In a possible implementation, an isolation optocoupler is also included; the output end of the switch drive circuit 2000 is electrically connected to the input end of the isolation optocoupler for receiving a switching signal; the output end of the isolation optocoupler is suitable for being electrically connected to the switch of the reactive compensation device for outputting a switching signal.

[0037] In a possible implementation, the switch driving circuit 2000 is provided with more than two output terminals, and the more than two output terminals are respectively electrically connected to the switches of more than two reactive compensation controllers in a one-to-one correspondence to issue a switching signal, preferably 8 output terminals, each of which has an output +12V level signal to provide a working signal for the secondary control circuit of the reactive compensation device (such as the zero-crossing trigger circuit of the thyristor). That is, the reactive compensation device is connected to the power system circuit to be compensated through its electronic switch (preferably a bidirectional thyristor), and the control end of the electronic switch is provided with a zero-crossing trigger circuit, and the switching signal input end of the zero-crossing trigger circuit is electrically connected to the output end of the switch driving circuit 2000 provided in the present application to obtain the switching signal of the controller.

[0038] Furthermore, the output end of the TMS320F28335 DSP is connected to a 74LS244 chip, and is electrically connected to the switch control end of the reactive power compensation device through the 74LS244 chip. The switching control signal of the TMS320F28335 DSP is driven by the 74LS244 chip, and the output signal pins OA0 and OA1 of the 74LS244 chip are respectively connected to two isolation optocouplers (using TLP521 optocouplers), and the output end of the TLP521 optocoupler is electrically connected to the switch control end of the reactive power compensation device, isolating the control signal from the output signal to ensure the stability of the controller output signal.

[0039] In a possible implementation, a relay output module is also included. The output end of the switch drive circuit 2000 is electrically connected to the control end of the relay of the relay output module, and the relay is opened and closed according to the switching signal received by the control end. The input end and the output end of the relay are connected to the control resistor of the trigger circuit (the switch of the reactive compensation device), and the control resistor is the control resistor that is connected to the output end of the controller as the input end of the trigger circuit in the trigger circuit and is switched and controlled. The relay receives the input signal output by the switch drive circuit 2000, the relay is closed, and the control resistor is short-circuited by the closed relay and is cut out of the trigger circuit, and then a signal for controlling the switch of the reactive compensation device to be closed is generated, the switch of the reactive compensation device is closed, and the reactive compensation device is connected to the power system to perform reactive compensation and filtering work. The relay receives the cut-off signal output by the switch drive circuit 2000, the input and output ends of the relay are cut off, the control resistor is put into the trigger circuit to work normally, and the trigger circuit generates a signal for controlling the switch of the reactive compensation device to be cut off, the switch of the reactive compensation device is cut off, and the reactive compensation device is cut off from the power system, and the reactive compensation and filtering work are stopped.

[0040] The output end of the switch drive circuit 2000 is connected to the relay control end of the relay module 6000 through the ULN2003 chip, and the ULN2003 chip is used to drive the relay load to operate and control the relay to open and close. The ULN2003 chip is a high-voltage and high-current Darlington transistor array chip. It has the characteristics of high current gain, high operating voltage, wide temperature range, and strong load capacity. Its main function is to increase the load capacity of the output module. It is also an inverter, which plays the role of inverting the level signal.

[0041] In a possible implementation, the voltage transformer 1110 collects voltage signals of the A-phase and C-phase lines of the power system bus to be reactively compensated (reactively compensated and filtered by the reactive compensation device). Both sides of the primary winding input end of the voltage transformer 1110 are electrically connected to the A-phase line and the C-phase line of the power system bus to be reactively compensated, respectively. The input end of the current signal circuit 1200 is electrically connected to the B-phase line of the power system.

[0042] In a possible implementation, the switch driving circuit 2000 uses the TMS320F28335 digital signal processing chip of Ti Company.

[0043] The TMS320F28335 DSP has the following features:

[0044] 1. The use of high-performance static CMOS technology reduces the power supply voltage to 3.3V, reducing the power consumption of the controller; the execution speed of 30MIPS shortens the instruction cycle to 33ns (30MHz), thereby improving the real-time control capability of the controller;

[0045] 2. On-chip FLASH program memory up to 32K words, data / program RAM up to 1.5K words, 544 words of dual-port RAM (DARAM) and 2K words of single-port RAM (SARAM);

[0046] 3. Expandable external memory, a total of 192K words: 64K words of program memory; 64K words of data memory; 64K words of I / O addressing space;

[0047] 4. Watchdog timer module (WDT);

[0048] 5. The minimum conversion time of the 10-bit A / D converter is 500ns. Two 8-channel input A / D converters or one 16-channel input A / D converter can be selected to be triggered by two event managers;

[0049] The TMS320F28335 DSP has a total of 144 pins, including two event management modules EVA and EVB, each of which includes: two 16-bit general-purpose timers, 8 16-bit pulse modulation (PWM) channels; 16 analog input (ADC) channels; a 4-pin serial peripheral interface module (SPI); a serial communication interface module (SCI); a CAN controller module, etc. Among them, Figure 5 The VREFHI pin and VREFLO pin shown in the figure are the ADC analog input high and low level reference voltage input terminals respectively, and the VCCA pin is the ADC analog supply voltage.

[0050] like Figure 3 As shown in FIG. 1 , the Ua and Uc line voltage signals and the IB current signal collected by the sampling circuit 1000 are connected to the ADCIN3 pin and the ADCIN2 pin of the DSP respectively. The A / D analog-to-digital conversion module interface design is shown in FIG. Figure 5 shown.

[0051] The reactive power compensation controller and its control circuit based on TMS320F28335 chip adopt the latest DSP digital signal processing chip to realize system control, with fast response speed, surface mount technology on the circuit board, strong anti-interference ability, large-screen Chinese display LCD, and friendly human-machine interface. This control circuit is suitable for users who need to filter harmonics and automatically compensate reactive power in machinery manufacturing, metallurgy, coal mining, chemical industry, oil fields, ports, etc., and can also be used as a controller in places without harmonic sources.

[0052] The TMS320F28335 digital signal processing chip collects the B-phase current signal of the transformer low-voltage side outlet cabinet and the A-phase and C-phase line voltage signals of the bus voltage through the sampling circuit 1000, and transmits them to the DSP for processing and analysis through the conditioning of the filter 1120 and the voltage follower 1130 in the sampling circuit 1000, and determines the branch that needs to be switched. Through the relay output module, the zero-crossing trigger circuit of the reactive compensation device switch is controlled to control the switching of the filter compensation branch. The connection structure of this chip with the sampling circuit 1000, the chip of the liquid crystal display module 4000 and the clock chip 5000 can be seen in Figure 6-7 .

[0053] In a possible implementation, the voltage follower 1130 is preferably OP07CD. The switch driving circuit 2000 uses a TMS320F28335 chip.

[0054] In a possible implementation, a detection circuit and a sampling display are also included; the detection output end of the sampling circuit 1000 is electrically connected to the input end of the detection circuit, and the output end of the detection circuit is electrically connected to the input end of the sampling display. The sampling display is provided with a display screen 4100 to display the detection result of the sampling circuit 1000. The sampling display adopts a liquid crystal display module 4000, and the display screen 4100 is a liquid crystal display. The detection circuit includes a voltage detection circuit, and the secondary winding output end of the voltage transformer 1110 serves as the detection output end of the voltage signal circuit 1100 (of the sampling circuit 1000), and is electrically connected to the input end of the voltage detection circuit. The output end of the voltage detection circuit is electrically connected to the input end of the sampling display. The voltage detection circuit can be a voltage detection circuit built into the TMS320F28335 chip. The secondary winding output end of the voltage transformer 1110 is electrically connected to the I / O pin of the chip to detect the voltage, and the chip is electrically connected to the chip of the liquid crystal display module 4000 to communicate and transmit the detection result; it can also be a voltmeter, and the measurement value signal output end of the voltmeter is electrically connected to the input end of the sampling display for communication.

[0055] Further, the detection circuit includes a current detection circuit, and the secondary winding output end of the current transformer is used as the detection output end of the current signal circuit 1200 (of the sampling circuit 1000), and is electrically connected to the input end of the current detection circuit. The output end of the current detection circuit is electrically connected to the input end of the sampling display. The current detection circuit can be a current detection circuit built into the TMS320F28335 chip. The secondary winding output end of the current transformer is electrically connected to the I / O pin of the chip to detect the current, and the chip is electrically connected to the chip of the liquid crystal display module 4000 to communicate and transmit the detection result. It can also be an ammeter, and the measurement value signal output end of the ammeter is electrically connected to the input end of the sampling display for communication.

[0056] In a possible implementation, the LCD module 4000 uses a RICH12864D-03 chip, which has a dot matrix of 128×64 and 18 pins. The chip interface design and connection structure of the TMS320F28335 DSP and the LCD module 4000 are shown in FIG. Figure 6 As shown. The background light of the LCD is controlled by the IOPC5 pin of the DSP I / O port, and the NPN transistor Q1 is used as a switch. Specifically: when the IOPC5 port is at a high level, Q1 enters the saturation zone, and the background light of the LCD is on, and the sampling test results such as the voltage and current values ​​can be well presented even in a dark environment. When there is no need to increase the brightness or display the measured value on the screen, the operation button 4200 or the keyboard on the outer wall of the controller protective shell 7000 is operated to make the IOPC5 port low. At this time, Q1 enters the cut-off zone, and the background light is turned off, which has an energy-saving effect.

[0057] In a possible implementation, a clock chip 5000 is further included as a timing controller, and the output end of the clock chip 5000 is electrically connected to the control end of the switch drive circuit 2000 (or to the power supply output end switch control end of the control circuit of the reactive compensation controller), and the switch drive circuit 2000 is switched on and off. The clock chip 5000 generates and outputs a switching signal at its output end according to time to control the switch drive circuit 2000 to open (normal operation) or close (cut off and not work). The clock chip 5000 outputs an input signal at a specific time, and the switch drive circuit 2000 is input between the sampling circuit 1000 and the switch of the reactive compensation device, and the voltage and current signals are received and the switch switching signal of the reactive compensation device is generated and output, so as to complete the work of the reactive compensation controller. The clock chip 5000 outputs a cut-off signal at a specific time, and the switch drive circuit 2000 is cut off, and no longer receives the voltage and current signals, and cannot generate and output the switch switching signal of the reactive compensation device, and the reactive compensation controller stops working, and the reactive compensation controller is invalid, and no information collection and switch control are performed.

[0058] Furthermore, the clock chip 5000 uses the X1226 clock chip as the time and calendar timing chip of the automatic switching controller. At the same time, the X1226 chip is also a 4k (512×8) EEPROM. The X1226 chip uses a 32.768KHz external crystal oscillator, and all compensation and adjustment components are integrated on the chip, eliminating external discrete components and an adjustment capacitor, which can save printing space and component costs. The real-time clock of the clock chip 5000 uses separate hour, minute, and second registers to track time. The calendar has separate date, week, month, and year registers, and has an automatic leap year correction function.

[0059] In addition, the 4k (512×8) EEPROM in the X1226 chip can also store power parameters such as the number of branches of the reactive compensation device / filter compensation device controlled by the reactive compensation controller and the switching threshold. Its output end is electrically connected to the input end of the switch drive circuit 2000. Such power parameters can be used as the basis for the reactive compensation controller to generate switching actions.

[0060] In a possible implementation, the connection structure between the clock chip 5000 and the TMS320F28335 DSP is as follows: Figure 7 As shown. A forward diode is connected between the VCC pin and the Vback pin of the clock chip 5000. When the system power is normally supplied, the system voltage +3.3V supplies power to the clock chip 5000 to ensure the accuracy of the clock time. When the controller is powered off and the system power is disconnected, the chip is powered by the battery BT1, which saves battery power while ensuring that the clock time is accurate and not lost.

[0061] According to another aspect of the present application, a reactive power compensation controller is provided. The reactive power compensation controller is provided with the control circuit of the reactive power compensation controller mentioned above.

[0062] In one possible implementation, the reactive power compensation controller includes a circuit carrier and a protective shell 7000; the circuit carrier is a circuit board or chip provided with a control circuit of the reactive power compensation controller, the circuit carrier is provided with a control circuit of the reactive power compensation controller, the circuit carrier is installed in the protective shell 7000, and a joint through-hole is provided on the side wall of the protective shell 7000, and the control circuit of the reactive power compensation controller is electrically connected to the power system and the switch of the reactive power compensation device located outside the protective shell 7000 respectively through the joint through-hole.

[0063] Further, the joint perforations are located at Figure 8 The back of the protective shell 7000 is provided with a connector at the connector perforation, and the corresponding wire is electrically connected to the external device through the connector. The distribution of the connector on the inner side wall of the protective shell 7000 is as shown in FIG. Fig. 9 As shown. PL, PN are AC 220V power input, UA, UB are A, B phase voltage input, IA+, IA- are A phase current input, 12V- (B1 ~ B8) is the output of the drive trigger board. The power supply voltage of the control circuit of the reactive power compensation controller can be freely selected, and the voltage range is AC and DC 110 ~ 265V and can be powered normally.

[0064] The control end of the TMS320F28335 chip, the control end of the power supply, the control end of the clock chip 5000 and the state parameter signal end interface are all electrically connected to the liquid crystal display module 4000, and the operating status of the three is collected and displayed in real time. The liquid crystal display module 4000 is also provided with corresponding control buttons, including an up key, a down key, a menu key and a confirmation key, for the operator to operate and control the three.

[0065] The reactive power compensation controller provided in this application has a friendly human-machine interface. The control circuit can be selected and controlled by the control button, which is easy to operate. Different output modes can be adopted according to different on-site environments and usage requirements to meet the requirements of the system. The output mode can be a +12V level output mode and a relay output mode. The operating status of the controller and data such as the power parameters of the power grid are displayed through a liquid crystal display with a dot matrix of 128×64. The X1226 clock chip is used to provide the controller with time, calendar and other information. At the same time, the X1226 chip is also a 4k (512×8) EEPROM, which can store a small amount of power parameters such as the number of filter compensation branches and switching thresholds.

[0066] The reactive power compensation controller can be switched on and off through automatic and manual control. In recent years, the country has attached increasing importance to the construction of intelligent power grids, and the safety requirements for high-power operations are also a top priority. With the development of power electronics technology, the controller can realize a variety of functions, which is consistent with the requirements of smart grids. The reactive power compensation controller can also add communication and event recording functions, so that the staff can monitor the underground power parameters in real time in the distribution room and detect abnormal conditions in time; the event recording function is also conducive to the staff to summarize the underground power parameters, providing a basis for maintenance, overhaul, expansion and other work.

[0067] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A control circuit of a reactive power compensation controller, characterized in that: include: Sampling circuit and switch driving circuit; The sampling circuit includes a voltage signal circuit, and the voltage signal circuit includes a voltage transformer, a filter and a voltage follower, wherein: the primary winding input end of the voltage transformer is suitable for being electrically connected to the power system circuit to be reactively compensated, the secondary winding output end of the voltage transformer is electrically connected to the input end of the filter, and the output end of the filter is electrically connected to the input end of the voltage follower; The output end of the voltage follower is electrically connected to the input end of the switch drive circuit. The switch drive circuit is suitable for generating and outputting a switching signal for controlling the switch of the reactive compensation device according to the signal output by the sampling circuit. The output end of the switch drive circuit is suitable for being electrically connected to the switch of the reactive compensation device.

2. The control circuit of the reactive power compensation controller according to claim 1, characterized in that: The sampling circuit also includes a current signal circuit, the input end of the current signal circuit is suitable for being electrically connected to the power system circuit to collect and detect its current signal, and the output end of the current signal circuit is electrically connected to the input end of the switch drive circuit.

3. The control circuit of the reactive power compensation controller according to claim 1, characterized in that: One side of the primary winding input end of the voltage transformer is electrically connected to a voltage dividing resistor, and one side of the primary winding input end is electrically connected to the power system circuit through the voltage dividing resistor.

4. The control circuit of the reactive power compensation controller according to claim 1, characterized in that: The voltage signal circuit also includes a second resistor, which is electrically connected between the two ends of the secondary winding of the voltage transformer, one end of the second resistor connected to the secondary winding of the voltage transformer is grounded, and the other end of the second resistor serves as the output end of the secondary winding and is used to be electrically connected to the input end of the filter.

5. The control circuit of the reactive power compensation controller according to claim 1, characterized in that: The voltage follower includes an error amplifier and a fifth resistor, the output end of the filter is electrically connected to the positive input terminal of the error amplifier, the fifth resistor is electrically connected between the negative input terminal of the error amplifier and the output end of the error amplifier, and the output end of the error amplifier is electrically connected to the input end of the switch drive circuit.

6. The control circuit of the reactive power compensation controller according to claim 5, characterized in that: The voltage follower further includes a fourth resistor, which is electrically connected between the output end of the filter and the positive input terminal of the error amplifier.

7. The control circuit of the reactive power compensation controller according to claim 1, characterized in that: Also includes isolation optocoupler; The output end of the switch driving circuit is electrically connected to the input end of the isolation optocoupler for receiving a switching signal; the output end of the isolation optocoupler is suitable for being electrically connected to the switch of the reactive power compensation device for outputting a switching signal.

8. A reactive power compensation controller, characterized in that: The reactive power compensation controller is provided with a control circuit of the reactive power compensation controller as claimed in any one of claims 1 to 7.

9. The reactive power compensation controller according to claim 8, characterized in that: include: Circuit carrier and protective shell; The circuit carrier is provided with a control circuit of the reactive compensation controller, and the circuit carrier is installed in the protective shell. The side wall of the protective shell is provided with a joint through-hole, and the control circuit of the reactive compensation controller is electrically connected to the power system and the switch of the reactive compensation device located outside the protective shell through the joint through-hole.

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