High-voltage power supply device and control method thereof

Abstract

The invention belongs to the technical field of high-voltage power supplies, and particularly discloses a high-voltage power supply device and a control method thereof. The device comprises a first control circuit, and a direct-current voltage source group, a relay switch group and a filter circuit which are connected in sequence, the DC voltage source group and the relay switch group are connected with the first control circuit. The first control circuit is used for controlling the direct-current voltage source group to output multiple paths of direct-current voltages with different voltage grades; controlling the on-off state of each path of relay in the relay switch group so as to gate a target direct current voltage in the multiple paths of direct current voltages; and the filter circuit is used for filtering the target direct current voltage and outputting the filtered target direct current voltage. According to the high-voltage power supply device, the power consumption of the high-voltage power supply device can be greatly reduced while the response speed of the power supply meets the requirement, the cost and the size of the device can be reduced, and the device is easy to miniaturize.

Description

Technical Field

[0001] The present application belongs to the technical field of high voltage power supply, and more specifically, to a high voltage power supply device and a control method thereof. Background Art

[0002] Periodically poled lithium niobate frequency doubling devices are used in many optical devices, such as narrow linewidth lasers required in precision measurement and quantum optics. They all require the use of periodically poled lithium niobate crystals or waveguides to convert the frequency of infrared lasers emitted by fiber lasers to obtain lasers of the required wavelength. In the preparation of periodically poled lithium niobate, high-voltage polarization is the core step. Taking into account the effects of leakage, thermal effects, domain dynamics, etc., in order to prepare periodically poled crystals with uniform polarization, good periodic consistency, and few defects, while avoiding overly complex electrode pattern preparation, it is essential to modulate the polarization voltage to form waveforms such as pulses and steps, which requires a fast-response high-voltage power supply.

[0003] At present, traditional fast-response high-voltage power supply devices usually generate stable high voltage through steps such as inversion, boost rectification, etc., and then use linear amplification to modulate the output high voltage. However, the high-voltage linear amplifier circuit operates in the linear region, which requires a large amount of power dissipation and has high power consumption. At the same time, since it requires a large number of active devices to be connected in series or use electric vacuum devices, the cost is also relatively high.

[0004] Therefore, how to better implement high voltage power supply devices has become a technical problem that needs to be solved urgently in the industry. Summary of the invention

[0005] In view of the defects of the prior art, the purpose of the present application is to better realize a high-voltage power supply device, aiming to solve the problems of high power consumption and high cost of the existing high-voltage power supply device.

[0006] To achieve the above objectives, in a first aspect, the present application provides a high voltage power supply device, comprising: A first control circuit, and a DC voltage source group, a relay switch group and a filter circuit connected in sequence; the DC voltage source group and the relay switch group are both connected to the first control circuit; The first control circuit is used to control the DC voltage source group to output multiple DC voltages of different voltage levels; control the switch state of each relay in the relay switch group to select the target DC voltage among the multiple DC voltages; The filter circuit is used to filter the target DC voltage and output the filtered target DC voltage.

[0007] Optionally, the DC voltage source group includes a plurality of DC voltage sources, each of which is used to output one DC voltage under the control of the first control circuit; The relay switch group includes a multi-channel relay; the filter circuit includes a multi-channel diode branch, a filter capacitor and a sampling resistor group, and the sampling resistor group includes two resistors connected in series; Each of the DC voltage sources is connected to one of the relays, and each of the relays is connected to one of the diode branches; The output ends of the diode branches are connected to one end of the filter capacitor, and the other end of the filter capacitor is grounded; one end of the filter capacitor is connected to one end of the sampling resistor group, and the other end of the sampling resistor group is grounded; one end of the filter capacitor serves as the output end of the filter circuit.

[0008] Optionally, each of the DC voltage sources includes a second control circuit, and a step-down circuit, an inverter circuit, a step-up rectifier circuit and a voltage sampling circuit connected in sequence; the step-down circuit and the voltage sampling circuit are both connected to the second control circuit; The step-down circuit is used to step down the input DC starting voltage and output a first DC voltage; The inverter circuit is used to convert the first DC voltage into a first AC voltage; The boost rectifier circuit is used to boost and rectify the first AC voltage and output a second DC voltage as the output of the DC voltage source; The voltage sampling circuit is used to collect the divided voltage of the second DC voltage; The second control circuit is used to control the output of the step-down circuit based on the divided voltage and a preset reference voltage to adjust the second DC voltage.

[0009] Optionally, the step-down circuit includes a first switch tube, a first diode, a first inductor and a first capacitor; the drain of the first switch tube serves as the input end of the step-down circuit; The gate of the first switch tube is connected to the output end of the second control circuit, the source of the first switch tube, one end of the first inductor and the cathode of the first diode are connected in common, the anode of the first diode and one end of the first capacitor are connected to the ground, and the other end of the first inductor is connected to the other end of the first capacitor; the other end of the first inductor serves as the output end of the step-down circuit.

[0010] Optionally, the second control circuit comprises an error amplifier and a comparator connected in sequence; the negative electrode of the error amplifier is connected to the output end of the voltage sampling circuit for receiving the divided voltage; the positive electrode of the error amplifier is used to receive the preset reference voltage; The error amplifier is used to output a voltage error signal between the divided voltage and the preset reference voltage; The comparator is used to output a PWM signal based on the voltage error signal and a preset carrier signal to control the switching state of the first switch tube and control the output of the buck circuit.

[0011] Optionally, the inverter circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a second inductor, a second capacitor, a second switch tube, a third switch tube, a second diode, a third diode, a fourth diode and a fifth diode; One end of the first resistor, one end of the second resistor, and one end of the second inductor are connected to the output end of the step-down circuit; the other end of the second inductor is connected to the first input end of the boost rectifier circuit; the other end of the first resistor, the anode of the fifth diode, the cathode of the second diode, and one end of the third resistor are connected to the gate of the second switch tube; the other end of the second resistor, the anode of the fourth diode, the cathode of the third diode, and one end of the fourth resistor are connected to the gate of the third switch tube; The anode of the second diode, the anode of the third diode, the source of the second switch tube and the source of the third switch tube are connected to the ground; the other end of the third resistor is connected to the other end of the fourth resistor; The cathode of the fourth diode, the drain of the second switch tube, and one end of the second capacitor are connected to the second input end of the boost rectifier circuit; the cathode of the fifth diode, the drain of the third switch tube, and the other end of the second capacitor are connected to the third input end of the boost rectifier circuit. Optionally, the boost rectifier circuit comprises a boost transformer and a rectifier filter circuit connected in sequence; The center tap of the primary winding of the boost transformer serves as the first input terminal of the boost rectifier circuit, the same-name end of the primary winding serves as the second input terminal of the boost rectifier circuit, and the opposite-name end of the primary winding serves as the third input terminal of the boost rectifier circuit; The step-up transformer is used to step up the first AC voltage to a second AC voltage according to a preset winding ratio; The rectification and filtering circuit is used to rectify and filter the second AC voltage and output the second DC voltage.

[0012] Optionally, the rectification and filtering circuit includes a sixth diode, a seventh diode, an eighth diode, a ninth diode, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor and a seventh capacitor; The sixth diode, the seventh diode, the eighth diode, the ninth diode, the third capacitor, the fourth capacitor, the fifth capacitor and the sixth capacitor are used to form a voltage doubler rectifier circuit to rectify and filter the second AC voltage; The seventh capacitor is used to filter out ripples in the output signal of the voltage doubler rectifier circuit.

[0013] Optionally, it further includes a load resistor and a low-end current sampling module; one end of the load resistor is connected to the output end of the filter circuit, and the other end of the load resistor is connected to the input end of the low-end current sampling module; The low-end current sampling module is used to sample and detect the current flowing through the load resistor.

[0014] In a second aspect, the present application provides a control method applied to any of the above-mentioned high-voltage power supply devices, comprising: Output multiple DC voltages with different voltage levels; Selecting a target DC voltage among the multiple DC voltages through relay switch control; The target DC voltage is filtered and the filtered target DC voltage is output.

[0015] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art: The present application provides a high-voltage power supply device and a control method thereof. The device includes a first control circuit, and a DC voltage source group, a relay switch group and a filter circuit connected in sequence. By introducing a combination of a DC voltage source group and a relay switch group, under the control of the control circuit, the DC voltage source group can generate multiple DC high-voltage sources that are nearly constant in a short period of time, and the high-voltage relays in the relay switch group can quickly switch the high-voltage source outputs of different channels to achieve a high response speed. Compared with traditional high-voltage power supply devices using linear amplification, the number of high-voltage resistant components required is greatly reduced, which can greatly reduce the power consumption of the high-voltage power supply device while ensuring that the power supply response speed meets the requirements, and can also reduce the cost and volume of the device, making it easy to miniaturize the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is one of the structural schematic diagrams of the high voltage power supply device provided in the embodiment of the present application; Figure 2 This is the second structural schematic diagram of the high voltage power supply device provided in the embodiment of the present application; Figure 3 is a schematic structural diagram of a DC voltage source in a high voltage power supply device provided in an embodiment of the present application; Figure 4 This is the third structural schematic diagram of the high-voltage power supply device provided in the embodiment of the present application; Figure 5 is a structural diagram of a low-end current sampling module provided in an embodiment of the present application; Figure 6It is a flow chart of a control method of a high-voltage power supply device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0018] The terms "first" and "second" in the specification and claims of this application are used to distinguish different objects rather than to describe a specific order of the objects. For example, a first control circuit and a second control circuit are used to distinguish control circuits with different functions rather than to describe a specific order of the control circuits.

[0019] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0020] In the description of the embodiments of the present application, unless otherwise specified, "multi-channel" means two or more channels. For example, multi-channel DC voltage refers to two or more DC voltages, etc.; multi-channel relays refer to two or more relays, etc.

[0021] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0022] Figure 1 is one of the structural schematic diagrams of the high voltage power supply device provided in the embodiment of the present application, such as Figure 1 As shown, including: A first control circuit 1, and a DC voltage source group 2, a relay switch group 3 and a filter circuit 4 connected in sequence; the DC voltage source group 2 and the relay switch group 3 are both connected to the first control circuit 1; The first control circuit 1 is used to control the DC voltage source group 2 to output multiple DC voltages of different voltage levels; control the switch state of each relay in the relay switch group 3 to select the target DC voltage among the multiple DC voltages; The filter circuit 4 is used for filtering the target DC voltage and outputting the filtered target DC voltage.

[0023] Specifically, the DC voltage source group described in the embodiment of the present application is used to output multiple DC voltages of different voltage levels, which can be specifically composed of multiple switching high-voltage DC sources, and the voltage level output by each high-voltage DC source can be different.

[0024] The target DC voltage described in the embodiment of the present application can be specifically selected according to the voltage level required for the actual lithium niobate polarization test.

[0025] The relay switch group described in the embodiment of the present application can specifically adopt a high-voltage relay group, which includes multiple high-voltage relay branches, wherein each high-voltage relay branch can adopt a reed switch relay with a maximum withstand voltage of 20kV and a current of 1A to control the on and off of each high-voltage DC source output, switch the outputs of multiple high-voltage DC sources, and form steep rising and falling edges.

[0026] It should be noted that a steep rising edge can be obtained through the action of the high-voltage relay group. Tests show that the rising and falling edge durations of the high-voltage relay are both less than 0.1ms, and the propagation delay is less than 3ms, which can achieve rapid switching of high voltage with a high response speed.

[0027] In an embodiment of the present application, under the control of the first control circuit 1, the DC voltage source group 2 can output multiple high-voltage DCs of different voltage levels, and each high-voltage DC source output is connected to the relay switch group 3. The first control circuit 1 controls the switching state of each high-voltage relay in the relay switch group 3, and selects the target DC voltage from the multiple DC voltages. In this way, rapid step switching of the high-voltage DC source can be achieved.

[0028] In the embodiment of the present application, considering that there is a jitter of about 1ms during the switching of the high-voltage relay, that is, the relay contact will oscillate between on and off, the output of the relay switch group 3 can be connected to each input end of the filter circuit 4. The filter circuit 4 can use a high-voltage filter, and after the target DC voltage is sent to the high-voltage filter, the target DC voltage can be filtered to filter out the noise signal generated by the jitter when the high-voltage relay is switched, so as to obtain the filtered target DC voltage.

[0029] Generally, lithium niobate polarization adopts a multi-pulse step-shaped voltage waveform. In an embodiment of the present application, a high-voltage DC waveform required for the periodic polarization of lithium niobate crystals can be generated, and the output of each high-voltage DC source is set at the platform of the set waveform through the control circuit. Exemplarily, assuming that the output of the device is set to a square wave with a peak value of 8kV and a valley value of 2kV, the output voltage of one DC voltage source in the DC voltage source group is set to 2kV, and the output voltage of another DC voltage source is set to 8kV. When the output voltage needs to be adjusted slowly, the control circuit changes the reference input voltage of the high-voltage source to achieve control of the output voltage. When the output voltage needs to change rapidly to produce a step, the control circuit switches the relay switch to achieve rapid adjustment of the output voltage.

[0030] For example, before the rising edge of the square wave, the first high-voltage relay connected in series with one DC voltage source is energized, and the second high-voltage relay connected in series with another DC voltage source is released, and the output voltage is 2 kV. When the rising edge arrives, the control circuit releases the first high-voltage relay and energizes the second high-voltage relay, and the output voltage is 8 kV, thereby obtaining the fast switching high voltage required for the polarization of lithium niobate.

[0031] The high-voltage power supply device of the embodiment of the present application includes a first control circuit, and a DC voltage source group, a relay switch group and a filter circuit connected in sequence. By introducing a combination of the DC voltage source group and the relay switch group, under the control of the control circuit, the DC voltage source group can generate multiple DC high-voltage sources that are nearly constant in a short period of time, and quickly switch the high-voltage source outputs of different channels through the high-voltage relays in the relay switch group to achieve a high response speed. Compared with traditional high-voltage power supply devices using linear amplification, the number of high-voltage resistant components required is greatly reduced, which can greatly reduce the power consumption of the high-voltage power supply device while ensuring that the power supply response speed meets the requirements, and can also reduce the cost and volume of the device, making it easy to miniaturize the device.

[0032] Figure 2 This is a second structural diagram of a high voltage power supply device provided in an embodiment of the present application, such as Figure 2 As shown, as an optional embodiment, the DC voltage source group 2 includes multiple DC voltage sources 21, each DC voltage source 21 is used to output a DC voltage under the control of the first control circuit; the relay switch group 3 includes multiple relays 31; the filter circuit 4 includes multiple diode branches 41, a filter capacitor Cout and a sampling resistor group 42, and the sampling resistor group 42 includes two resistors connected in series, namely, a resistor RH and a resistor RL; Each DC voltage source 21 is connected to a relay 31, and each relay 31 is connected to a diode branch 41. The output ends of the diode branches 41 are connected to one end of the filter capacitor Cout, and the other end of the filter capacitor Cout is grounded; one end of the filter capacitor Cout is connected to one end of the sampling resistor group 42, and the other end of the sampling resistor group 42 is grounded; one end of the filter capacitor Cout serves as the output end of the filter circuit 4.

[0033] Specifically, in an embodiment of the present application, the DC voltage source group 2 includes multiple DC voltage sources 21, such as a high voltage power source 1, a high voltage power source 2, ..., a high voltage power source N, where N is determined by the desired number of output voltage steps. At the same time, each DC voltage source 21 is connected to a relay 31, and each relay 31 is connected to a diode branch 41. It can be understood that the number of DC voltage sources 2, relay switch groups 3, and diode branches 41 can be set to be the same.

[0034] Among them, each DC voltage source 21 is used to generate a high voltage DC that is approximately constant in a short period of time, which is supplied to the subsequent relay switching, and the output voltage can be set to 0-10kV. It should be noted that this range can be adjusted according to actual needs; its response speed can be much lower than the output speed of the high voltage power supply device, for example, it can be set to 1s. Of course, this value can also be determined according to the actual circuit.

[0035] In an embodiment of the present application, the first control circuit 1 can communicate with a computer to generate a regulating voltage of a high-voltage DC source and a switch signal of a high-voltage relay. Specifically, the first control circuit 1 can output a regulating voltage VADJ[1,…,N] for regulating and controlling each high-voltage power supply under the control of a computer instruction, wherein the regulating voltage VADJ1 is input into the high-voltage power supply 1, the regulating voltage VADJ2 is input into the high-voltage power supply 2, and the regulating voltage VADJN is input into the high-voltage power supply N, thereby controlling the output of each high-voltage power supply.

[0036] At the same time, the first control circuit 1 can also output a relay control signal RELAY[1, ..., N] for controlling the switch state of each relay in the relay switch group 3 under the control of a computer instruction, wherein the relay control signal RELAY1 is input to the first relay, the relay control signal RELAY2 is input to the second relay, and the relay control signal RELAYN is input to the Nth relay. In this way, the on and off of each relay can be controlled, thereby ensuring that the target DC voltage can be selected from the DC voltage output by each high-voltage power supply.

[0037] In the embodiment of the present application, the filter circuit 4 can be composed of multiple diode branches 41, filter capacitor Cout and sampling resistor group 42, wherein each diode branch 41 can use a high-voltage diode. In this way, through the isolation of the high-voltage diode, the voltage output by each high-voltage power supply can be prevented from flowing back, and the relay jitter can be avoided when the output terminal is switched, causing multiple high-voltage source output terminals set to different output voltages to be connected and cause damage. After the diode is isolated, each output terminal is connected in parallel, and the filter capacitor Cout and the sampling resistor group 42 form a low-pass filter to filter out the noise generated by the relay jitter. H and R L A voltage divider circuit is formed, which can be used to collect the output voltage to the control board. One end of the filter capacitor Cout is used as the output end of the filter circuit 4 to output the filtered target DC voltage.

[0038] The device of the embodiment of the present application can avoid the need for a linear high-voltage amplifier by setting up multi-channel relay switching. It only needs to use a switching high-voltage power supply with a slower response speed. It has a simple structure and is easy to implement. It can generate the high-voltage waveform required for the periodic polarization of lithium niobate, and can be programmed through the host computer software to generate different polarization voltage waveforms to meet experimental needs. The more important feature is that the use of a high-voltage switching DC source and relay switching reduces the cost and volume of the system and improves efficiency and reliability.

[0039] Figure 3 2 is a schematic diagram of the structure of a DC voltage source in a high-voltage power supply device provided in an embodiment of the present application. Each DC voltage source 21 includes a second control circuit 211, and a step-down circuit 212, an inverter circuit 213, a step-up rectifier circuit 214 and a voltage sampling circuit 215 connected in sequence; the step-down circuit 212 and the voltage sampling circuit 215 are both connected to the second control circuit 211; The step-down circuit 212 is used to step down the input DC starting voltage and output a first DC voltage; The inverter circuit 213 is used to convert the first DC voltage into a first AC voltage; The boost rectifier circuit 214 is used to boost and rectify the first AC voltage and output a second DC voltage as an output of the DC voltage source; The voltage sampling circuit 215 is used to collect the divided voltage of the second DC voltage; The second control circuit 211 is used to control the output of the step-down circuit based on the divided voltage and a preset reference voltage to adjust the second DC voltage.

[0040] Specifically, the DC startup voltage described in the embodiment of the present application refers to an input voltage used to start the operation of the DC voltage source, which can be represented by POWER_IN. For example, the DC startup voltage can specifically be the voltage output by a DC 12V power supply.

[0041] The first DC voltage described in the embodiment of the present application refers to a DC voltage obtained by stepping down an input DC starting voltage by a step-down circuit.

[0042] The first AC voltage described in the embodiment of the present application refers to an AC voltage obtained by rectifying and inverting the input first DC voltage through an inverter circuit, which is a high-frequency AC signal.

[0043] The second DC voltage described in the embodiment of the present application refers to the DC voltage output by the boost rectifier circuit after boosting, rectifying and filtering the first AC voltage, which serves as the output of the final DC voltage source.

[0044] The preset reference voltage described in the embodiment of the present application refers to a pre-set DC reference voltage, which can be expressed as VREF, and is used to guide the DC voltage source to output a DC voltage specified by the user for adjustment. Specifically, it can be output by controlling the first control circuit through user instructions as the aforementioned adjustment voltage.

[0045] In the embodiment of the present application, each DC voltage source 21 can be composed of a second control circuit 211, and a step-down circuit 212, an inverter circuit 213, a boost rectifier circuit 214 and a voltage sampling circuit 215 connected in sequence. Among them, the step-down circuit 212 can specifically use a BUCK step-down circuit for pre-stage voltage regulation, step down the input DC starting voltage, and output a first DC voltage. Then, through the inverter circuit 213, the first DC voltage can be converted into high-frequency AC power, that is, the first AC voltage is obtained.

[0046] In the embodiment of the present application, the first AC voltage output by the inverter circuit 213 is transmitted to the boost rectifier circuit 214, and the boost rectifier circuit 214 can perform boost and rectifier filtering processing on the first AC voltage according to a preset high transformation ratio, such as 1:30, and output a second DC voltage, which is transmitted as the output of the DC voltage source to the voltage sampling circuit 215. Further, the voltage sampling circuit 215 can collect the divided voltage of the second DC voltage through a series resistor voltage divider circuit.

[0047] Furthermore, in the embodiment of the present application, the step-down circuit 212 and the voltage sampling circuit 215 are connected to the second control circuit 211, and the second control circuit 211 can obtain the divided voltage through the voltage sampling circuit 215. Furthermore, the second control circuit 211 can use the divided voltage and the preset reference voltage to perform error compensation control to control the output of the step-down circuit and adjust the DC voltage output by the final boost rectifier circuit 214.

[0048] The device of the embodiment of the present application constructs various high-voltage DC voltage sources by utilizing a step-down circuit, an inverter circuit, a boost rectifier circuit, a voltage sampling circuit and a control circuit, and protects subsequent circuits through a BUCK step-down circuit. The boost rectifier circuit provides a high-voltage DC output, and the voltage sampling circuit provides feedback information. The control circuit then adjusts the output voltage of the voltage source based on this information, thereby effectively achieving stable output and precise control of the high-voltage DC voltage source.

[0049] Continue to refer to Figure 3 As an optional embodiment, the buck circuit 212 includes a first switch tube Q1, a first diode D1, a first inductor L1 and a first capacitor C1; the drain of the first switch tube Q1 serves as the input end of the buck circuit 212; The gate of the first switch tube Q1 is connected to the output end of the second control circuit 211, the source of the first switch tube Q1, one end of the first inductor L1 and the cathode of the first diode D1 are connected in common, the anode of the first diode D1 and one end of the first capacitor C1 are connected to the ground, and the other end of the first inductor L1 is connected to the other end of the first capacitor C1; the other end of the first inductor L1 serves as the output end of the buck circuit 212.

[0050] Specifically, in the embodiment of the present application, the buck circuit 212 adopts a BUCK buck circuit, which may specifically include a first switch tube Q1, a first diode D1, a first inductor L1 and a first capacitor C1.

[0051] Optionally, the switch tubes in the embodiments of the present application may all be MOS tubes.

[0052] In an embodiment of the present application, by periodically controlling the on and off of the first switch tube Q1, utilizing the energy storage and release characteristics of the first inductor L1, and the unidirectional conductivity of the first diode D1, the input DC starting voltage can be stepped down and converted into a lower output voltage, that is, the first DC voltage is output.

[0053] The device of the embodiment of the present application uses a switching tube, a diode, an inductor and a capacitor to construct a step-down circuit. By adjusting the duty cycle of the switching tube, the step-down circuit can achieve a wide adjustment range of the output voltage, thereby providing a stable and reliable power supply for the subsequent inverter circuit.

[0054] Continue to refer to Figure 3 As an optional embodiment, the second control circuit 211 includes an error amplifier EA and a comparator U1 connected in sequence; the negative electrode of the error amplifier EA is connected to the output end of the voltage sampling circuit 215 for receiving the divided voltage; the positive electrode of the error amplifier EA is used to receive a preset reference voltage; The error amplifier EA is used to output a voltage error signal between the divided voltage and a preset reference voltage; The comparator U1 is used to output a PWM signal based on the voltage error signal and the preset carrier signal to control the switching state of the first switch tube Q1 and control the output of the buck circuit 212 .

[0055] Specifically, in the embodiment of the present application, the second control circuit 211 may adopt a combination of an error amplifier EA and a comparator U1, and the error amplifier EA and the comparator U1 are connected in sequence. Among them, the positive electrode of the error amplifier EA is used to receive a preset reference voltage, and the negative electrode is connected to the output end of the voltage sampling circuit 215, and is used to receive the divided voltage of the second DC voltage. Thus, the error amplifier EA determines whether the output voltage deviates from the set value by detecting the difference between the output voltage and the reference voltage.

[0056] Furthermore, once the error amplifier EA detects the error signal, it will amplify it and output an amplified voltage error signal. The amplified voltage error signal is used to drive the subsequent comparator U1 to generate a PWM control signal.

[0057] In an embodiment of the present application, the positive electrode of the comparator U1 receives a preset carrier signal from an oscillator or other signal source, and the preset carrier signal can specifically be a sawtooth wave or square wave signal with a fixed frequency; the negative electrode of the comparator U1 receives a voltage error signal output from the error amplifier EA, and then compares the preset carrier signal with the voltage error signal. When the voltage of the preset carrier signal is higher than the voltage of the voltage error signal, the comparator U1 outputs a high level; otherwise, it outputs a low level. In this way, the output of the comparator U1 forms a PWM signal, and its duty cycle changes with the change of the error signal.

[0058] The PWM signal can be used to control the switching state of the first switch tube Q1 in the buck circuit 212. When the PWM signal is at a high level, the first switch tube Q1 is turned on; when the PWM signal is at a low level, the first switch tube Q1 is turned off. By adjusting the duty cycle of the PWM signal, the output voltage of the buck circuit 212 can be accurately controlled.

[0059] The device of the embodiment of the present application, by utilizing a control circuit constructed by an error amplifier EA and a comparator U1, and utilizing a PWM signal to control the on and off of a switch tube in a buck circuit, can effectively perform stable regulation and efficient energy conversion on the output voltage of the buck circuit, thereby achieving stable regulation and efficient control of the output of a high-voltage DC voltage source.

[0060] Continue to refer to Figure 3As an optional embodiment, the inverter circuit 213 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a second inductor L2, a second capacitor C2, a second switch tube Q2, a third switch tube Q3, a second diode D2, a third diode D3, a fourth diode D4 and a fifth diode D5; One end of the first resistor R1, one end of the second resistor R2, and one end of the second inductor L2 are connected to the output end of the step-down circuit 212; the other end of the second inductor L2 is connected to the first input end of the step-up rectifier circuit 214; the other end of the first resistor R1, the anode of the fifth diode D5, the cathode of the second diode D2, and one end of the third resistor R3 are connected to the gate of the second switch tube Q2; the other end of the second resistor R2, the anode of the fourth diode D4, the cathode of the third diode D3, and one end of the fourth resistor R4 are connected to the gate of the third switch tube Q3; The anode of the second diode D2, the anode of the third diode D3, the source of the second switch tube Q2 and the source of the third switch tube Q3 are connected to the ground; the other end of the third resistor R3 is connected to the other end of the fourth resistor R4; The cathode of the fourth diode D4, the drain of the second switch tube Q2, and one end of the second capacitor C2 are connected to the second input end of the boost rectifier circuit 214; the cathode of the fifth diode D5, the drain of the third switch tube Q3, and the other end of the second capacitor C2 are connected to the third input end of the boost rectifier circuit 214. Specifically, in an embodiment of the present application, the inverter circuit 213 may specifically adopt a self-excited oscillation circuit, which may specifically be composed of a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a second inductor L2, a second capacitor C2, a second switch tube Q2, a third switch tube Q3, a second diode D2, a third diode D3, a fourth diode D4 and a fifth diode D5.

[0061] By utilizing the alternating conduction of the two switch MOS tubes and the unidirectional conductivity of the diode, the second capacitor C2 is continuously charged and discharged, and the current and voltage in the circuit will form a periodic oscillation, thereby inverting the input first DC voltage into a high-frequency AC power and outputting the first AC voltage. The inverter circuit 213 operates in a resonant state, which reduces switching losses and improves efficiency.

[0062] The device of the embodiment of the present application adopts a self-excited oscillation circuit to construct an inverter circuit, and the control circuit is simple, has strong anti-interference ability, and has a low manufacturing cost, which is beneficial to further improve the stability of the entire device circuit and reduce the device cost.

[0063] Continue to refer to Figure 3 As an optional embodiment, the boost rectifier circuit 214 includes a boost transformer T1 and a rectifier filter circuit 2141 connected in sequence; The center tap of the primary winding of the boost transformer T1 serves as the first input terminal of the boost rectifier circuit 214, the same-name end of the primary winding serves as the second input terminal of the boost rectifier circuit 214, and the opposite-name end of the primary winding serves as the third input terminal of the boost rectifier circuit 214; The step-up transformer T1 is used to step up the first AC voltage to a second AC voltage according to a preset winding ratio; The rectifying and filtering circuit 2141 is used to rectify and filter the second AC voltage and output a second DC voltage.

[0064] Specifically, the preset transformation ratio information described in the embodiment of the present application refers to the preset winding ratio information of the step-up transformer, which can be set according to actual design requirements.

[0065] The second AC voltage described in the embodiment of the present application refers to the AC voltage output after the first AC voltage is boosted by a boost transformer.

[0066] In the embodiment of the present application, the boost transformer T1 may be a high-frequency high-voltage transformer. After the first AC voltage output by the inverter circuit 213 is transmitted to the boost transformer T1, the first AC voltage may be boosted to a second AC voltage according to preset winding ratio information.

[0067] Furthermore, the rectifying and filtering circuit 2141 in the boost rectifying circuit 214 performs rectification and filtering on the second AC voltage, and converts the second AC voltage into a second DC voltage.

[0068] Continue to refer to Figure 3 As an optional embodiment, the rectifier and filter circuit 2141 includes a sixth diode D6, a seventh diode D7, an eighth diode D8, a ninth diode D9, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6 and a seventh capacitor C7; The sixth diode D6, the seventh diode D7, the eighth diode D8, the ninth diode D9, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5 and the sixth capacitor C6 are used to form a voltage doubling rectifier circuit to rectify and filter the second AC voltage; The seventh capacitor C7 is used to filter out ripples in the output signal of the voltage doubler rectifier circuit.

[0069] Specifically, in the embodiment of the present application, the sixth diode D6, the seventh diode D7, the eighth diode D8 and the ninth diode D9 can all be high-voltage diodes, and the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6 and the seventh capacitor C7 can all be high-voltage capacitors. One end of the third capacitor C3 is connected to the same-name end of the secondary winding of the step-up transformer T1, and the other end is connected to the cathode of the sixth diode D6, the anode of the seventh diode D7 and one end of the fifth capacitor C5; the anode of the sixth diode D6 is connected to the ground with one end of the fourth capacitor C4, one end of the seventh capacitor C7 and the opposite-name end of the secondary winding of the step-up transformer T1; the other end of the fourth capacitor C4 is connected to the other end of the seventh diode D7, the anode of the eighth diode and one end of the sixth capacitor C6; the other end of the sixth capacitor C6 is connected to the cathode of the ninth diode D9 and the other end of the seventh capacitor; the other end of the fifth capacitor C5 is connected to the cathode of the eighth diode D6 and the anode of the ninth diode D9.

[0070] In the embodiment of the present application, diodes D6, D7, D8, D9, and capacitors C3, C4, C5, C6 together form a voltage doubler rectifier circuit to rectify and filter the second AC voltage. Figure 3 As shown, the voltage doubling rectifier circuit is a four-fold voltage rectifier circuit. When the transformer outputs a positive half cycle (the polarity at the same-name end is positive), diodes D7 and D9 are turned on, D6 and D8 are turned off, and capacitors C4 and C6 are charged to twice the peak value of the second AC voltage; when the transformer outputs a negative half cycle (the polarity at the same-name end is negative), diodes D6 and D8 are turned on, D7 and D9 are turned off, capacitor C3 is charged to the peak value of the second AC voltage, and C5 is charged to twice the peak value of the second AC voltage. Therefore, the output voltage is the voltage on C4 and C6 in series, which is equivalent to four times the peak value of the second AC voltage. The seventh capacitor C7 is used to further filter out ripples.

[0071] It should be noted that in the embodiments of the present application, the voltage doubling rectifier circuit is not limited to quadruple voltage, and can adopt a structure of no voltage doubling, double voltage or any multiple voltage doubling according to the output voltage requirements.

[0072] The device of the embodiment of the present application can effectively ensure that the output DC voltage is smooth and stable by constructing a rectifier and filter circuit using high-voltage diodes and high-voltage capacitors. It also has a simple structure and is easy to operate, which is conducive to further reducing the cost of the device.

[0073] Further, in the embodiment of the present application, the high voltage output of the rectifier filter circuit 2141 is sampled by the fifth resistor R5 and the sixth resistor R6 in the voltage sampling circuit 215, and a divided voltage can be output. For example, the divided voltage can be reduced to 1 / 2000 of the output second DC voltage. Furthermore, the divided voltage and the preset reference voltage VREF input by the first control circuit 1 are sent to the error amplifier EA, and the output end of EA is connected to the comparator U1 to generate a PWM signal to drive the first switch tube Q1 in the buck circuit 212 to adjust the output of the buck circuit 212.

[0074] Figure 4 This is the third structural diagram of the high voltage power supply device provided in the embodiment of the present application, such as Figure 4 As shown, the device also includes a load resistor RLoad and a low-end current sampling module 5; one end of the load resistor RLoad is connected to the output end of the filter circuit 4, and the other end of the load resistor RLoad is connected to the input end of the low-end current sampling module 5; The low-end current sampling module 5 is used to sample and detect the current flowing through the load resistor RLoad.

[0075] Specifically, in the embodiment of the present application, low-end detection is adopted, a low-end current sampling module 5 is introduced, and a transimpedance amplifier input is used to suppress the power frequency interference of the circuit. Considering that the current changes greatly during the polarization process of lithium niobate, a gear switching function is designed to detect the current in the range of nA to mA. The low-end current sampling module 5 samples and detects the current flowing through the load resistor RLoad, and outputs the detection current I out .

[0076] In the embodiment of the present application, the first control circuit 1 can also collect the detection current I out , and the voltage divider V between resistors RH and RL out At the same time, it can also receive control instructions and commands from the host computer and convert the collected voltage data V out , current data I out The voltage and current signals collected by the acquisition circuit are converted into digital signals by the analog-to-digital converter and packaged and transmitted by the first control circuit 1. The first control circuit 1 can also control the switching of the gear of the current sampling circuit.

[0077] More specifically, the first control circuit 1 may be composed of a single chip microcomputer, an analog-to-digital converter ADC and a digital-to-analog converter DAC. The analog-to-digital converter ADC is used to collect the output voltage data V out and current data I outThe digital-to-analog converter DAC is used to set the output voltage for each DC voltage source 21; the logic outputs of the single-chip microcomputer drive each relay 31 to switch. The single-chip microcomputer is connected to the computer through the serial port, receives the control data edited on the computer, and uploads the real-time voltage and current detection data packets to the computer.

[0078] Figure 5 is a schematic diagram of the structure of the low-end current sampling module provided in the embodiment of the present application, such as Figure 5 As shown, in an embodiment of the present application, the low-end current sampling module 5 can be composed of a transimpedance amplifier, a switch K1, resistors R7, R8 and R9. When the low-end current sampling module 5 is in a large range, the switch K1 is disconnected, and the transimpedance amplifier gain is small; when switched to a small range, the switch K1 is closed to form a T-type resistor network, and the transimpedance amplifier gain is large. When the input current increases rapidly and the range switching lags behind, the output of the transimpedance amplifier reaches the power rail voltage, and the input resistance is only (R7+R8), which is much smaller than the resistance of the direct switching resistor, avoiding the input voltage being too high and causing burning.

[0079] The device of the embodiment of the present application introduces a low-end current sampling module to sample and detect the output current of the device, and can monitor the current condition of the rear-end load of the power supply device in real time, which helps to trigger the protection mechanism in time when the current is overloaded, such as cutting off the power supply or reducing the output power, to prevent the power supply device and the load from being damaged due to overcurrent, thereby improving the reliability and safety of the high-voltage power supply device.

[0080] The control method of the high-voltage power supply device provided in the present application is described below. The control method of the high-voltage power supply device described below and the high-voltage power supply device described above can be referenced to each other.

[0081] Figure 6 is a flow chart of a control method of a high-voltage power supply device provided in an embodiment of the present application, which can be applied to any of the above-mentioned high-voltage power supply devices, such as Figure 6 As shown, the method includes: Step S1, outputting multiple DC voltages of different voltage levels; Step S2, selecting a target DC voltage among multiple DC voltages through relay switch control; Step S3, filtering the target DC voltage and outputting the filtered target DC voltage.

[0082] It can be understood that the detailed embodiments of the above method can refer to the introduction of the detailed functional implementation of each unit / module in the above device embodiment, which will not be repeated here.

[0083] It should be understood that the above method is applied to the device in the above embodiment. The implementation principle and technical effect of the method are similar to the description of the corresponding program module in the above device. The corresponding process in the method can refer to the working process of the device and will not be repeated here.

[0084] The control method of the high-voltage power supply device in the embodiment of the present application, by introducing a combination of a DC voltage source group and a relay switch group, can enable the DC voltage source group to generate multiple DC high-voltage sources that are close to constant in a short period of time under the control of a control circuit, and quickly switch the high-voltage source outputs of different channels through the high-voltage relays in the relay switch group to achieve a high response speed. Compared with the traditional high-voltage power supply device using linear amplification, the number of high-voltage resistant components required is greatly reduced, and the power consumption of the high-voltage power supply device can be greatly reduced while ensuring that the power supply response speed meets the requirements, and the cost and volume of the device can also be reduced, making it easy to miniaturize the device.

[0085] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC.

[0086] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions may be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.

[0087] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0088] It should be understood that expressions such as "including" and "may include" that may be used in the present application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In the present application, terms such as "including" and / or "having" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0089] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the relative position relationship after connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after connection. The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only reference directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0090] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A high voltage power supply device, characterized in that: include: A first control circuit, and a DC voltage source group, a relay switch group and a filter circuit connected in sequence; The DC voltage source group and the relay switch group are both connected to the first control circuit; The first control circuit is used to control the DC voltage source group to output multiple DC voltages of different voltage levels; control the switch state of each relay in the relay switch group to select the target DC voltage among the multiple DC voltages; The filter circuit is used to filter the target DC voltage and output the filtered target DC voltage.

2. The high voltage power supply device according to claim 1, characterized in that: The DC voltage source group includes a plurality of DC voltage sources, each of which is used to output one DC voltage under the control of the first control circuit; The relay switch group includes a multi-way relay; The filtering circuit includes a multi-way diode branch, a filtering capacitor and a sampling resistor group, and the sampling resistor group includes two resistors connected in series; Each of the DC voltage sources is connected to one of the relays, and each of the relays is connected to one of the diode branches; The output ends of the diode branches are connected to one end of the filter capacitor, and the other end of the filter capacitor is grounded; one end of the filter capacitor is connected to one end of the sampling resistor group, and the other end of the sampling resistor group is grounded; one end of the filter capacitor serves as the output end of the filter circuit.

3. The high voltage power supply device according to claim 2, characterized in that: Each of the DC voltage sources comprises a second control circuit, and a step-down circuit, an inverter circuit, a step-up rectifier circuit and a voltage sampling circuit connected in sequence; the step-down circuit and the voltage sampling circuit are both connected to the second control circuit; The step-down circuit is used to step down the input DC starting voltage and output a first DC voltage; The inverter circuit is used to convert the first DC voltage into a first AC voltage; The boost rectifier circuit is used to boost and rectify the first AC voltage and output a second DC voltage as the output of the DC voltage source; The voltage sampling circuit is used to collect the divided voltage of the second DC voltage; The second control circuit is used to control the output of the step-down circuit based on the divided voltage and a preset reference voltage to adjust the second DC voltage.

4. The high voltage power supply device according to claim 3, characterized in that: The step-down circuit comprises a first switch tube, a first diode, a first inductor and a first capacitor; the drain of the first switch tube serves as the input end of the step-down circuit; The gate of the first switch tube is connected to the output end of the second control circuit, the source of the first switch tube, one end of the first inductor and the cathode of the first diode are connected in common, the anode of the first diode and one end of the first capacitor are connected to the ground, and the other end of the first inductor is connected to the other end of the first capacitor; the other end of the first inductor serves as the output end of the step-down circuit.

5. The high voltage power supply device according to claim 4, characterized in that: The second control circuit comprises an error amplifier and a comparator connected in sequence; the negative electrode of the error amplifier is connected to the output end of the voltage sampling circuit for receiving the divided voltage; the positive electrode of the error amplifier is used to receive the preset reference voltage; The error amplifier is used to output a voltage error signal between the divided voltage and the preset reference voltage; The comparator is used to output a PWM signal based on the voltage error signal and a preset carrier signal to control the switching state of the first switch tube and control the output of the buck circuit.

6. The high voltage power supply device according to claim 3, characterized in that: The inverter circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a second inductor, a second capacitor, a second switch tube, a third switch tube, a second diode, a third diode, a fourth diode and a fifth diode; One end of the first resistor, one end of the second resistor, and one end of the second inductor are connected to the output end of the step-down circuit; the other end of the second inductor is connected to the first input end of the boost rectifier circuit; the other end of the first resistor, the anode of the fifth diode, the cathode of the second diode, and one end of the third resistor are connected to the gate of the second switch tube; the other end of the second resistor, the anode of the fourth diode, the cathode of the third diode, and one end of the fourth resistor are connected to the gate of the third switch tube; The anode of the second diode, the anode of the third diode, the source of the second switch tube and the source of the third switch tube are connected to the ground; the other end of the third resistor is connected to the other end of the fourth resistor; The cathode of the fourth diode, the drain of the second switch tube, and one end of the second capacitor are connected to the second input end of the boost rectifier circuit; the cathode of the fifth diode, the drain of the third switch tube, and the other end of the second capacitor are connected to the third input end of the boost rectifier circuit.

7. The high voltage power supply device according to claim 6, characterized in that: The boost rectifier circuit comprises a boost transformer and a rectifier filter circuit connected in sequence; The center tap of the primary winding of the boost transformer serves as the first input terminal of the boost rectifier circuit, the same-name end of the primary winding serves as the second input terminal of the boost rectifier circuit, and the opposite-name end of the primary winding serves as the third input terminal of the boost rectifier circuit; The step-up transformer is used to step up the first AC voltage to a second AC voltage according to a preset winding ratio; The rectification and filtering circuit is used to rectify and filter the second AC voltage and output the second DC voltage.

8. The high voltage power supply device according to claim 7, characterized in that: The rectification and filtering circuit comprises a sixth diode, a seventh diode, an eighth diode, a ninth diode, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor and a seventh capacitor; The sixth diode, the seventh diode, the eighth diode, the ninth diode, the third capacitor, the fourth capacitor, the fifth capacitor and the sixth capacitor are used to form a voltage doubler rectifier circuit to rectify and filter the second AC voltage; The seventh capacitor is used to filter out ripples in the output signal of the voltage doubler rectifier circuit.

9. The high voltage power supply device according to any one of claims 1 to 8, characterized in that: It also includes a load resistor and a low-end current sampling module; one end of the load resistor is connected to the output end of the filter circuit, and the other end of the load resistor is connected to the input end of the low-end current sampling module; The low-end current sampling module is used to sample and detect the current flowing through the load resistor.

10. A control method applied to the high voltage power supply device according to any one of claims 1 to 9, characterized in that: include: Output multiple DC voltages with different voltage levels; Selecting a target DC voltage among the multiple DC voltages through relay switch control; The target DC voltage is filtered and the filtered target DC voltage is output.

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