EDI power supply circuit for preparing ultrapure water

Abstract

The utility model provides an EDI power supply circuit used for ultrapure water preparation. The EDI power supply circuit comprises a rectification module, a chopping module, a voltage sampling module, a driving module and a first control module. The input end of the rectifier module is connected with three-phase alternating current input, and the output end is connected with the input end of the chopper module; the chopping module comprises an IGBT (Insulated Gate Bipolar Translator), and an emitter and a collector of the IGBT are respectively connected between the input end and the output end of the chopping module; the chopping module is suitable for converting a direct current input into an adjustable direct current output voltage required by an EDI (Electronic Data Interchange) process; the input end of the voltage sampling module is connected with the output end of the chopper module, and the output end is connected with the input end of the control module; the output end of the first control module is connected with the input end of the driving module; the output end of the driving module is connected with the grid electrode of the IGBT. According to the utility model, controllable conversion of the power supply is realized by using one IGBT, so that the hardware cost and the assembly complexity are obviously reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of preparing ultrapure water using EDI technology, and in particular relates to an EDI power supply circuit used for preparing ultrapure water. Background Art

[0002] In traditional EDI power supply design, thyristor SCR is usually used as the core component of the design solution. This solution is based on phase-controlled rectification technology and is mainly used to convert alternating current (AC) power into direct current (DC) power for use in EDI modules.

[0003] In EDI applications, the power supply system usually includes transformers, rectifier bridges (composed of multiple thyristors), filter capacitors and other components. When AC power is input, the pulsation of the DC output voltage can be changed by adjusting the triggering moment of the thyristor (i.e., the conduction angle), thereby affecting the average value of the output voltage. This method enables the power supply to dynamically adapt to the voltage requirements of the EDI module within a certain range.

[0004] In order to achieve more precise voltage control and higher power output, traditional solutions often require multiple thyristors to be used in parallel or series, which not only increases hardware costs, but also makes circuit design more complicated and increases the difficulty of maintenance and troubleshooting. Utility Model Content

[0005] In view of this, the utility model provides an EDI power supply circuit for ultrapure water preparation, which effectively controls hardware costs while ensuring precise voltage control and higher power output.

[0006] In order to solve the above technical problems, the technical solutions provided by the utility model are as follows:

[0007] An EDI power supply circuit for ultrapure water preparation, comprising:

[0008] A rectifier module, a chopper module, a voltage sampling module, a drive module and a first control module;

[0009] The input end of the rectifier module is connected to the three-phase AC input, and the output end is connected to the input end of the chopper module;

[0010] The chopper module includes an IGBT, and the emitter and collector of the IGBT are respectively connected between the input terminal and the output terminal of the chopper module;

[0011] The chopper module is suitable for converting the DC input into an adjustable DC output voltage suitable for the EDI process;

[0012] The input end of the voltage sampling module is connected to the output end of the chopping module, and the output end is connected to the input end of the control module;

[0013] The output end of the first control module is connected to the input end of the driving module;

[0014] The output terminal of the driving module is connected to the gate of the IGBT.

[0015] Preferably, the chopping module further includes: a first diode, a first resistor and a first capacitor;

[0016] The emitter of the IGBT is connected to the anode of the first diode and one end of the first resistor, the cathode of the first diode and the other end of the first resistor are both connected to one end of the first capacitor, and the other end of the first capacitor is connected to the collector of the IGBT.

[0017] As preferably, it also includes: a voltage conversion module;

[0018] The input end of the voltage conversion module is connected to a preset voltage input, and the output end is respectively connected to the collector of the IGBT and one end of the second resistor, and the other end of the second resistor is connected to the gate of the IGBT.

[0019] Preferably, it also includes: a current sampling module;

[0020] The input end of the current sampling module is connected to the output end of the chopping module.

[0021] Preferably, it further comprises: an auxiliary power supply module;

[0022] The input end of the auxiliary power module is connected to the three-phase AC input, and the output end supplies power to each module in the EDI power circuit.

[0023] Preferably, it also includes: a fault indicator light module;

[0024] The fault indicator light module is connected to the monitoring module of the EDI power supply circuit through a connector.

[0025] Preferably, the fault indicator light module includes: a power indicator light, a DSP error indicator light and a working indicator light.

[0026] As a preferred embodiment, it also includes: a network port module;

[0027] The interface of the network port module is connected between the external device and the EDI power supply circuit.

[0028] Preferably, the system further comprises: a fault resetting module.

[0029] Preferably, the voltage sampling module and the driving module are both optical couplers.

[0030] In summary, the utility model provides an EDI power supply circuit for ultrapure water preparation, including: a rectifier module, a chopper module, a voltage sampling module, a drive module and a first control module; the input end of the rectifier module is connected to a three-phase AC input, and the output end is connected to the input end of the chopper module; the chopper module includes an IGBT, and the emitter and collector of the IGBT are respectively connected between the input end and the output end of the chopper module; the chopper module is suitable for converting a DC input into an adjustable DC output voltage suitable for the EDI process; the input end of the voltage sampling module is connected to the output end of the chopper module, and the output end is connected to the input end of the control module; the output end of the first control module is connected to the input end of the drive module; and the output end of the drive module is connected to the gate of the IGBT. The utility model uses an IGBT to realize the controllable conversion of the power supply, which significantly reduces the hardware cost and assembly complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A structural block diagram of an EDI power supply circuit for ultrapure water preparation provided by an embodiment of the utility model;

[0033] Figure 2 A circuit diagram of a rectifier module provided in an embodiment of the utility model;

[0034] Figure 3 A circuit structure diagram of a chopper module provided in an embodiment of the utility model;

[0035] Figure 4 A circuit diagram of a voltage sampling module provided in an embodiment of the utility model;

[0036] Figure 5 A circuit structure diagram of a driving module provided in an embodiment of the utility model;

[0037] Figure 6 This is a circuit structure diagram of the first control module provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0038] In order to make the purpose, features and advantages of the utility model more obvious and easy to understand, the technical scheme in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the embodiment described below is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0039] In the description of the present application, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, if the term "plurality" appears, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0040] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0041] See also Figure 1-2 , this embodiment provides an EDI power supply circuit for ultrapure water preparation, comprising:

[0042] A rectifier module, a chopper module, a voltage sampling module, a drive module and a first control module;

[0043] The input end of the rectifier module is connected to the three-phase AC input, and the output end is connected to the input end of the chopper module;

[0044] The chopper module includes an IGBT, and the emitter and collector of the IGBT are respectively connected between the input terminal and the output terminal of the chopper module;

[0045] The chopper module is suitable for converting the DC input into an adjustable DC output voltage suitable for the EDI process;

[0046] The input end of the voltage sampling module is connected to the output end of the chopping module, and the output end is connected to the input end of the control module;

[0047] The output end of the first control module is connected to the input end of the driving module;

[0048] The output terminal of the driving module is connected to the gate of the IGBT.

[0049] It should be noted that the rectifier module realizes the rectification function. The three-phase AC power supply (W, U, V) passes through the rectifier module, which usually contains a bridge rectifier circuit (such as a three-phase full-wave rectifier bridge) to convert the input three-phase AC voltage into a pulsating DC voltage. This conversion is achieved by utilizing the unidirectional conductivity of the diode to ensure that the current flows in only one direction, providing DC input for the subsequent chopper module.

[0050] The rectified DC voltage enters the chopper module. The core of this module is an insulated gate bipolar transistor (IGBT), which is a high-speed, high-efficiency switching element. Its function is to quickly open and close under the drive of the control signal, thereby "chopping" (i.e., modulating) the input DC voltage. The emitter of the IGBT is connected to the input end of the chopper module (i.e., the rectified DC power supply), and the collector is connected to the output end. By adjusting the on-time and off-time ratio (duty cycle) of the IGBT, the average voltage level output to the EDI unit can be effectively adjusted to adapt to different processing requirements.

[0051] In order to ensure the stability and accurate adjustment of the output voltage, the voltage sampling module is used to monitor the voltage level at the output of the chopper module. This sampled voltage is sent to the first control module, which can be a microprocessor-based digital controller or an analog circuit, which calculates the necessary control signal based on the difference between the preset target voltage and the actual sampled voltage to adjust the switching behavior of the IGBT.

[0052] The driver module receives the signal from the first control module and converts it into a driving voltage suitable for the IGBT gate to control the switching state of the IGBT. This means that when the output voltage needs to be increased, the control module will command the driver module to keep the IGBT on for a longer time in each switching cycle, and vice versa.

[0053] The working process of this embodiment during implementation is as follows: after the system receives the start signal, the three-phase AC power passes through the rectifier module. The rectifier bridge (usually a three-phase bridge rectifier circuit) inside the module converts the AC voltage into a pulsating DC voltage, providing a basis for subsequent voltage regulation.

[0054] The pulsating DC voltage is then input to the chopper module. The IGBT plays a key role here, controlling its on and off according to the instructions of the first control module. When the IGBT is turned on, the current flows through the IGBT to the output terminal, increasing the output voltage; when the IGBT is turned off, the current path is cut off and the output voltage no longer increases. By quickly and continuously changing the on-time (duty cycle) of the IGBT, the average output voltage can be accurately adjusted to meet the needs of the EDI process.

[0055] The voltage sampling module monitors the output voltage of the chopper module in real time, and converts this voltage value into an electrical signal and sends it back to the first control module. This feedback mechanism is the basis for realizing closed-loop control.

[0056] The first control module compares the target voltage with the feedback voltage, calculates the difference between the two, and then generates a control signal based on the difference and the built-in control algorithm (such as PID control algorithm). This signal is sent to the drive module.

[0057] The driver module amplifies the control signal to an appropriate voltage level sufficient to drive the IGBT, and then connects it to the gate of the IGBT through a dedicated drive circuit. This process ensures fast and precise switching of the IGBT.

[0058] Through the above closed-loop control cycle, the system continuously compares the actual output with the set target and automatically adjusts the IGBT switching strategy to maintain the stability and accuracy of the output voltage to meet the strict voltage requirements of the EDI unit.

[0059] In a specific implementation of this embodiment, it is possible to use Figure 2-6 The circuit structure shown below is combined with Figure 2-6 This embodiment is further described.

[0060] See also Figure 2 SGBJ3510 is a bridge rectifier component, commonly used in the power rectifier part of the circuit. In this embodiment, it is used to realize the function of the rectifier module. Among them, ports 2-4 are connected to the three-phase AC input, and ports 1 and 5 are output terminals, which are connected to the chopper module.

[0061] See also Figure 3 , the IGBT of the chopper module is selected as IKW25N120H3. The IGBT (IKW25N120H3) is used as the main switch element, and its collector is connected to the positive pole of the power supply, and the emitter is connected to the load side. It is turned on and off by controlling its gate signal, thereby controlling the current flowing through the load. The IGBT is also connected to a freewheeling element (such as a first diode D1, a first resistor, and a first capacitor), which provides a path for the current to continue to flow to the load during the IGBT shutdown period to ensure continuous current output. In some embodiments, the emitter of the IGBT is connected to the positive pole of the first diode and one end of the first resistor, the negative pole of the first diode and the other end of the first resistor are both connected to one end of the first capacitor, and the other end of the first capacitor is connected to the collector of the IGBT. In addition, a filter module can be connected after the DC chopper circuit to smooth the output voltage and current, reduce ripple, and make the output more stable. The filter module is usually composed of an inductor (L filter) and a capacitor (C filter), and sometimes a resistor is added to form an LC filter circuit or a more complex π-type filter circuit.

[0062] See also Figure 4 The voltage sampling module is implemented using HCNR200-00E and several LM358Ds. The first LM358D is used as a pre-processing stage for the input signal, for signal buffering, gain adjustment or filtering to ensure that the signal is suitable for further processing. Its output is connected to the inverting input of the second LM358D, which usually means that the second LM358D is used as a gain stage, in which the output of the first LM358D is used as a reference signal. The second LM358D is used as a signal gain stage. According to the configuration (setting the feedback resistor and input resistor through the resistor divider network), the required gain can be set to amplify the signal processed by the first LM358D. Its output is connected to the LED interface of HCNR200-00E, which means that the output voltage of the second LM358D is indirectly converted into an optical signal by controlling the current of the LED. The LED interface receives the current control signal from the second LM358D and converts it into an optical signal. The internal photodiodes PD1 and PD2 detect this optical signal, where PD1 is used for internal feedback to maintain the stability of the output, and PD2 converts the optical signal back to an electrical signal. The third LM358D has its input connected to the PD2 interface of HCNR200-00E to receive the weak electrical signal isolated and converted by the optocoupler. The third LM358D is usually configured as a voltage follower or gain amplifier to restore and enhance the output signal of PD2, ensure the integrity of the signal and provide sufficient driving capability. Its output VCY is connected to the first control module as the output of the entire circuit.

[0063] See also Figure 5 , the first control module is implemented by SG3525ADW and several LM324DRs, where the first LM324DR on the input side acts as a voltage comparator or amplifier to receive the signal VCY from the voltage sampling module (i.e., the output of the third LM3525D mentioned above). The function of this stage is to perform preliminary processing on the sampled voltage, such as amplification, filtering or comparison, to meet the needs of subsequent control logic. The subsequent several LM324DRs work together to further process and / or combine the signals of the previous stages to provide appropriate control signals for SG3525ADW. SG3525ADW is a pulse width modulation controller, whose IN+ port receives the control signal to determine the duty cycle of the final PWM output. SG3525ADW generates PWM signals based on the signal processing of the previous stages to drive external circuits such as switching power supplies, motor control, etc. SG3525ADW has internal oscillators, comparators, latches and other control logic, and can adjust the PWM output according to the input signal.

[0064] See also Figure 6, the drive module is implemented using TLP250, and the PWM signal generated by the first control module is first sent to the input end of TLP250. This PWM signal contains a series of pulses with adjustable width, which is used to control the size of the output power. The input side of TLP250 usually includes an LED (light-emitting diode). When the PWM signal is at a high level, the LED is turned on and emits light. The light emitted by the LED is received by the photosensitive element (usually a photosensitive transistor) inside the TLP250, which converts the light signal into an electrical signal. This process achieves electrical isolation to prevent noise or voltage spikes on the high-voltage side from affecting the control circuit. The output side of TLP250 usually includes a transistor with an open collector output (OC output), which changes the output state according to the received light intensity (i.e., the duty cycle of the PWM signal). In order to drive high-power devices such as IGBTs, the output of TLP250 is usually connected to a push-pull circuit or an appropriate pull-up / pull-down resistor is added to provide sufficient drive current and voltage. In this way, the duty cycle change of the PWM signal is converted into the intensity change of the corresponding drive signal. The enhanced drive signal is sent to the gate of the IGBT. When the PWM signal is at a high level (pulse width), the output of TLP250 turns on the IGBT, allowing current to flow through; and during the low level period, the IGBT is turned off, cutting off the current flow. In this way, by adjusting the duty cycle of the PWM signal, the on-time of the IGBT can be controlled, thereby controlling the average voltage or current output to the load, and realizing chopper modulation.

[0065] In addition, the circuit structure of this embodiment may also include: a voltage conversion module; the input end of the voltage conversion module is connected to the preset voltage input, the output end is respectively connected to the collector of the IGBT and one end of the second resistor, and the other end of the second resistor is connected to the gate of the IGBT. The voltage conversion module is implemented by NE555D and transformer DRT803 / 111B. It may also include: a current sampling module; the input end of the current sampling module is connected to the output end of the chopper module, which can be implemented by CC6920SO-10A. It also includes: an auxiliary power supply module; the input end of the auxiliary power supply module is connected to the three-phase AC input, and the output end supplies power to each module in the EDI power supply circuit. The auxiliary power supply module is implemented by AYL12-G_380Vac. It also includes: a fault indicator light module; the fault indicator light module is connected to the monitoring module of the EDI power supply circuit through a connector. The fault indicator light module includes: a power indicator light, a DSP error indicator light and a working indicator light. It also includes: a network port module; the interface of the network port module is connected between the external device and the EDI power supply circuit. The network port module can be implemented by HR913550A. It also includes: a fault reset module.

[0066] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An EDI power supply circuit for ultrapure water preparation, characterized in that: include: A rectifier module, a chopper module, a voltage sampling module, a drive module and a first control module; The input end of the rectifier module is connected to the three-phase AC input, and the output end is connected to the input end of the chopper module; The chopper module comprises an IGBT, the emitter and collector of the IGBT are respectively connected between the input end and the output end of the chopper module; The chopper module is adapted to convert a DC input into an adjustable DC output voltage suitable for the EDI process; The input end of the voltage sampling module is connected to the output end of the chopping module, and the output end is connected to the input end of the control module; The output end of the first control module is connected to the input end of the driving module; The output end of the driving module is connected to the gate of the IGBT.

2. The EDI power supply circuit for preparing ultrapure water according to claim 1, characterized in that: The chopping module also includes: a first diode, a first resistor and a first capacitor; The emitter of the IGBT is connected to the anode of the first diode and one end of the first resistor, the cathode of the first diode and the other end of the first resistor are both connected to one end of the first capacitor, and the other end of the first capacitor is connected to the collector of the IGBT.

3. The EDI power supply circuit for preparing ultrapure water according to claim 2, characterized in that: Also includes: Voltage conversion module; The input end of the voltage conversion module is connected to a preset voltage input, and the output end is respectively connected to the collector of the IGBT and one end of a second resistor, and the other end of the second resistor is connected to the gate of the IGBT.

4. The EDI power supply circuit for ultrapure water preparation according to claim 1, characterized in that: Also includes: Current sampling module; The input end of the current sampling module is connected to the output end of the chopping module.

5. The EDI power supply circuit for preparing ultrapure water according to claim 1, characterized in that: Also includes: Auxiliary power supply module; The input end of the auxiliary power supply module is connected to the three-phase AC input, and the output end supplies power to each module in the EDI power supply circuit.

6. The EDI power supply circuit for preparing ultrapure water according to claim 1, characterized in that: Also includes: Fault indicator light module; The fault indicator light module is connected to the monitoring module of the EDI power supply circuit through a connector.

7. The EDI power supply circuit for preparing ultrapure water according to claim 6, characterized in that: The fault indicator light module includes: a power indicator light, a DSP error indicator light and a working indicator light.

8. The EDI power supply circuit for preparing ultrapure water according to claim 1, characterized in that: Also includes: Network port module; The interface of the network port module is connected between the external device and the EDI power supply circuit.

9. The EDI power supply circuit for preparing ultrapure water according to claim 1, characterized in that: Also includes: Fault reset module.

10. The EDI power supply circuit for ultrapure water preparation according to claim 1, characterized in that: The voltage sampling module and the driving module are both optical couplers.

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