A high voltage generator power supply

Abstract

The invention discloses a high-voltage generator power supply. The high-voltage generator power supply comprises a main control unit, an interface unit, a rectifying and filtering unit, a first inverter unit, a second inverter unit and a high-voltage oil tank. The main control unit is respectively connected to the interface unit, the rectifying and filtering unit, the first inverter unit, the second inverter unit and the high-voltage oil tank. The input end of the rectifying and filtering unit is connected to an AC voltage. The output end of the rectifying and filtering unit is respectively connected to the input end of the first inverter unit and the second inverter unit. The output end of the first inverter unit and the second inverter unit is respectively connected to the high-voltage oil tank. The high-voltage value output by the high-voltage generator power supply can not only be adjusted and set, but also the second high-voltage value outputted takes the first high-voltage value as a reference potential, so that the high-voltage generator power supply can be directly connected to an X-ray tube controlled by a gate-controlled switch to power it.

Description

Technical Field

[0001] The invention relates to a high voltage generator power supply, in particular to a high voltage generator power supply applied to an X-ray tube with a gate controlled switch. Background Art

[0002] The X-ray tube is the main component of current X-ray radiation imaging equipment and is the component that generates X-rays. X-rays are generated by high-speed electrons bombarding a metal target with a high atomic weight. A typical X-ray tube includes a metal anode target and a cathode electron source. In the prior art, the high-voltage generator power supply and the X-ray tube are two independent components, which are connected together by a high-voltage cable to provide the required high voltage for the X-ray tube.

[0003] In order to accurately control the exposure sequence and exposure dose of the focus in a multi-focus X-ray source, a gate-controlled switch is usually used to control the voltage added to the X-ray tube to control the X-ray tube to output and shut down the X-ray. In the power supply requirements of some X-ray tubes with gate-controlled switches, a high-voltage generator power supply is required to provide two high voltages at the same time; however, the currently commonly used high-voltage generator power supplies all have only one high-voltage output, and therefore cannot meet the power supply requirements of the above-mentioned X-ray tubes with gate-controlled switches. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a high voltage generator power supply.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A high-voltage generator power supply, characterized in that it includes a main control unit, an interface unit, a rectifier and filter unit, a first inverter unit, a second inverter unit and a high-voltage oil tank, wherein the main control unit is respectively connected to the interface unit, the rectifier and filter unit, the first inverter unit, the second inverter unit and the high-voltage oil tank, the input end of the rectifier and filter unit is connected to an AC voltage, the output end of the rectifier and filter unit is respectively connected to the input end of the first inverter unit and the second inverter unit, and the output end of the first inverter unit and the second inverter unit is respectively connected to the high-voltage oil tank, so that the high-voltage oil tank outputs a first high-voltage value and a second high-voltage value.

[0007] Preferably, of the two high voltages output by the high-pressure oil tank, one high voltage is used to be loaded between the cathode target and the anode target of the X-ray tube, and the other high voltage is used to control the output and shutoff of the X-rays of the X-ray tube through the grid control circuit of the X-ray tube.

[0008] Preferably, the main control unit is respectively provided with an operational amplifier, an analog / digital conversion chip, a first CAN interface, a second CAN interface, a first signal interface, a second signal interface and a third signal interface, the input end of the operational amplifier is connected to the high-pressure oil tank, the output end of the operational amplifier is connected to the input end of the analog / digital conversion chip, the output end of the analog / digital conversion chip is connected to the microcontroller of the main control unit, and the microcontroller is respectively connected to the first CAN interface and the second CAN interface; the second CAN interface is respectively connected to the interface unit, the rectifier and filter unit, the first inverter unit, the second inverter unit and the high-pressure oil tank, the first signal interface and the second signal interface are respectively connected to the first inverter unit and the second inverter unit, and the third signal interface is connected to the high-pressure oil tank.

[0009] Preferably, the rectification and filtering unit includes a three-phase full-bridge rectifier circuit, a microcontroller and a filtering circuit, the input end of the three-phase full-bridge rectifier circuit is connected to an AC voltage, the output end of the three-phase full-bridge rectifier circuit is connected to the input end of the filtering circuit, and the output end of the filtering circuit is respectively connected to the input ends of the first inverter unit and the second inverter unit.

[0010] Preferably, the rectification and filtering unit is provided with a soft start circuit and a first sampling circuit; the soft start circuit is arranged between the AC voltage and the three-phase full-bridge rectifier circuit and connected to the microcontroller, and the first sampling circuit is respectively connected to the output ends of the microcontroller and the filtering circuit.

[0011] Preferably, the slow start circuit comprises a thermistor, a main relay and an auxiliary relay, one end of the normally open contact of the main relay is correspondingly connected to one end of the thermistor and each phase of the AC voltage, the other end of the thermistor is correspondingly connected to one end of the normally open contact of the auxiliary relay, the other ends of the normally open contacts of the main relay and the auxiliary relay are respectively connected to the input end of the three-phase full-bridge rectifier circuit, and the normally open contacts of the main relay and the auxiliary relay are also respectively connected to the microcontroller.

[0012] Preferably, a phase loss detection protection circuit is provided in the filtering circuit, and the phase loss detection protection circuit includes a voltage comparator, the non-phase input terminal of the voltage comparator is connected to the first sampling circuit, the inverting input terminal of the voltage comparator is connected to the reference voltage, and the output terminal of the voltage comparator is connected to the microcontroller.

[0013] Preferably, the first inverter unit and the second inverter unit respectively include a microcontroller, a control module, a drive module and a full-bridge inverter circuit; the microcontroller is connected to the main control unit on the one hand, and is connected to the control module on the other hand, the control module is connected to the drive module, the drive module is connected to the input end of the full-bridge inverter circuit, and the output end of the full-bridge inverter circuit is connected to the high-pressure oil tank.

[0014] Preferably, a heat sink, a temperature detection chip and a current transformer are provided in the full-bridge inverter circuit, and the heat sink, the temperature detection chip and the current transformer are respectively connected to the microcontroller of each inverter unit.

[0015] Preferably, the high-voltage oil tank is provided with a first isolation transformer, a second isolation transformer, an oil tank interface board, a first voltage doubling rectifier circuit, a second voltage doubling rectifier circuit, a microcontroller and an operational amplifier; the primary terminals of the first isolation transformer and the second isolation transformer, the microcontroller and the operational amplifier are respectively connected to the oil tank interface board, the secondary terminal of the first isolation transformer is connected to the input terminal of the first voltage doubling rectifier circuit, the secondary terminal of the second isolation transformer is connected to the input terminal of the second voltage doubling rectifier circuit, the output terminal of the first voltage doubling rectifier circuit is connected to the first high-voltage output terminal of the high-voltage oil tank, and the output terminal of the second voltage doubling rectifier circuit is connected to the second high-voltage output terminal of the high-voltage oil tank; the second high-voltage output terminal is connected to the first high-voltage output terminal on the one hand, and is grounded on the other hand.

[0016] Preferably, a second sampling circuit and a third sampling circuit are respectively arranged in the high-pressure oil tank, the input end of the second sampling circuit is connected to the output end of the first voltage doubling rectifier circuit, the output end of the second sampling circuit is respectively connected to the first high-voltage output end and the output end of the third sampling circuit, the input end of the third sampling circuit is connected to the output end of the second voltage doubling rectifier circuit, and the output end of the third sampling circuit is connected to the second high-voltage output end; the second sampling circuit and the third sampling circuit are also respectively connected to the oil tank interface board.

[0017] The high-voltage generator power supply provided by the present invention can provide two-way high-voltage output through a main control unit, an interface unit, a rectifier and filter unit, a first inverter unit, a second inverter unit and a high-voltage oil tank. The output high-voltage value can not only be adjusted and set, but also the output second high-voltage value uses the first high-voltage value as a reference potential, so that the high-voltage generator power supply can be directly connected to an X-ray tube controlled by a gate-controlled switch to power it. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The schematic diagram of the high voltage generator power supply provided by the present invention;

[0019] Figure 2 A schematic diagram of a slow start circuit in a high voltage generator power supply provided by the present invention;

[0020] Figure 3 A schematic diagram of a phase loss detection protection circuit in a high voltage generator power supply provided by the present invention;

[0021] Figure 4 This is a schematic diagram of the high-voltage oil tank in the high-voltage generator power supply provided by the present invention. DETAILED DESCRIPTION

[0022] The technical content of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0023] like Figure 1 As shown, the high-voltage generator power supply provided by the present invention includes a main control unit 1, an interface unit 2, a rectifying and filtering unit 3, a first inverter unit 4, a second inverter unit 5 and a high-voltage oil tank 6. The main control unit 1 is respectively connected to the interface unit 2, the rectifying and filtering unit 3, the first inverter unit 4, the second inverter unit 5 and the high-voltage oil tank 6, the interface unit 2 is connected to input and output signals for user use, the input end of the rectifying and filtering unit 3 is connected to the AC voltage, the output end of the rectifying and filtering unit 3 is respectively connected to the input end of the first inverter unit 4 and the second inverter unit 5, and the output end of the first inverter unit 4 and the second inverter unit 5 is respectively connected to the high-voltage oil tank 6, so that the high-voltage oil tank 6 outputs the first high-voltage value and the second high-voltage value.

[0024] Among them, the high-pressure oil tank 6 outputs two high voltages, one high voltage is used to be loaded between the cathode target and the anode target of the X-ray tube, and the other high voltage is used to control the output and shutdown of the X-ray tube through the grid control circuit of the X-ray tube.

[0025] Among them, the main control unit 1 can be implemented by a control chip composed of a microcontroller (MCU) and an FPGA (Field-Programmable-Gate-Array). This control chip provides CAN communication function and the function of data transmission with the outside; and the FPGA is used to convert the timing signal input by the user into the timing required inside the high-voltage generator power supply, for example, when the user needs the high-voltage generator power supply to output and stop outputting the first high-voltage value (KV1) and the second high-voltage value (KV2).

[0026] An operational amplifier, an A / D conversion chip (analog-to-digital conversion chip), a first CAN interface, a second CAN interface, a first signal interface, a second signal interface and a third signal interface are respectively arranged on the control chip composed of a microcontroller and an FPGA. The input end of the operational amplifier is connected to the high-pressure oil tank 6, the output end of the operational amplifier is connected to the input end of the A / D conversion chip, the output end of the A / D conversion chip is connected to the microcontroller, and the microcontroller is respectively connected to the first CAN interface and the second CAN interface; the high-voltage signal output by the high-pressure oil tank 6 is amplified by the operational amplifier, and the amplified voltage and current signals are converted into digital signals by the A / D conversion chip, and then transmitted to the microcontroller for high-voltage, undervoltage, overcurrent and other judgments and protection. The first CAN interface is reserved for user system integration, for example, it can receive the timing signal input by the user. The second CAN interface is respectively connected to the interface unit 2, the rectifier and filter unit 3, the first inverter unit 4, the second inverter unit 5 and the high-pressure oil tank 6 through the corresponding CAN bus, so that the data transmission of the interface unit 2, the rectifier and filter unit 3, the first inverter unit 4, the second inverter unit 5 and the high-pressure oil tank 6 adopts the CAN communication form, which can reduce the cable interconnection of each part. The first signal interface and the second signal interface are respectively connected to the first inverter unit 4 and the second inverter unit 5 through corresponding data cables, so as to realize the control of the operating status of the first inverter unit 4 and the second inverter unit 5; the third signal interface is connected to the high-voltage oil tank 6 through the data cable, so as to send the voltage and current signals output by the high-voltage oil tank 6 to the main control unit 1, so as to facilitate the main control unit 1 to realize the closed-loop control of the first high voltage value and the second high voltage value output by the high-voltage generator power supply.

[0027] The interface unit 2 is implemented by an interface board (interface circuit board). The interface board is internally provided with an optical coupler for isolating each input and output signal, thereby isolating the high voltage inside the power supply of the high voltage generator from the high voltage in the user system.

[0028] The rectifier and filter unit 3 includes a three-phase full-bridge rectifier circuit, a microcontroller and a filter circuit. The input end of the three-phase full-bridge rectifier circuit is connected to an AC voltage (AC380V voltage), the output end of the three-phase full-bridge rectifier circuit is connected to the input end of the filter circuit, and the output end of the filter circuit is respectively connected to the input ends of the first inverter unit 4 and the second inverter unit 5. The rectifier and filter unit 3 realizes control and rectification filtering of the input AC voltage, and outputs a DC voltage (such as converting AC380V voltage into DC570V voltage). The three-phase full-bridge rectifier circuit and the filter circuit are existing three-phase full-bridge rectifier circuits and filter circuits, and their structures and working principles are not repeated here.

[0029] In order to reduce the instantaneous increase in the current of the filter capacitor of the filter circuit when the rectifying and filtering unit 3 is powered on, a slow start circuit 12 and a first sampling circuit 13 may be provided in the rectifying and filtering unit 3. Figure 2 As shown, the slow start circuit 12 includes negative temperature coefficient thermistors R1-R3, a main relay K1 and an auxiliary relay K2, one end of the normally open contact of the main relay K1 is connected to one end of the negative temperature coefficient thermistors R1-R3 and each phase of the AC voltage, the other end of the negative temperature coefficient thermistors R1-R3 is connected to one end of the normally open contact of the auxiliary relay K2, and the other ends of the normally open contacts of the main relay K1 and the auxiliary relay K2 are respectively connected to the input end of the three-phase full-bridge rectifier circuit; the first sampling circuit 13 includes a first sampling resistor and a second sampling resistor, and the first sampling resistor and the second sampling resistor are connected in series and respectively connected to the output end of the filter circuit; the microcontroller of the rectifier and filter unit 3 is respectively connected between the first sampling resistor and the second sampling resistor, and the normally open contacts of the main relay K1 and the auxiliary relay K2.

[0030] The timing mode of the slow start circuit is in the form of a negative temperature coefficient thermistor and a control relay (main relay K1 and auxiliary relay K2). By this method, the current value of the moment when the filter capacitor of the filter circuit is powered on can be reduced. If there is no such measure, the moment when the filter capacitor is powered on will cause the overcurrent protector of the power grid to be disconnected. The implementation process of the slow start circuit 12 and the first sampling circuit 13 is as follows: at the time of AC380V access, the main relay K1 does not absorb and charge, and the auxiliary relay K2 absorbs and charges the filter capacitor first. Because each circuit in this charging loop is connected in series with resistors R1-R3, this instantaneous charging current has been limited, and a small current is used to gradually charge the filter capacitor. The charging voltage of the filter capacitor is sampled and fed back to the microcontroller through the first sampling resistor and the second sampling resistor. When the feedback voltage value reaches a predetermined value, the microcontroller makes the main relay K1 absorb and charge. Because a certain voltage has been precharged, there will be no large current mutation at the moment of absorption and finally disconnect the auxiliary relay K2.

[0031] Since the capacitance of the filter capacitor in the filter circuit is very large, there must be a discharge measure for the filter capacitor after power failure to discharge all the charges stored in the filter capacitor to prevent electric shock to others. The specific discharge measure is to connect a discharge resistor in parallel at both ends of the filter capacitor.

[0032] Since the high-voltage generator power supply is a high-power high-voltage power supply, it has strict requirements on the power supply of the power grid. Therefore, it is necessary to set a phase loss detection protection circuit in the filter circuit; Figure 3As shown, the phase-loss detection protection circuit is composed of a voltage comparator, the positive input end of the voltage comparator is connected between the two sampling resistors of the first sampling circuit 13, the negative input end of the voltage comparator is connected to the reference voltage, the output end of the voltage comparator is connected to the microcontroller, and the microcontroller is also connected to the second CAN interface of the main control unit through the CAN bus; the voltage value of the filter capacitor of the sampling filter circuit is fed back to the voltage comparator through the first sampling resistor and the second sampling resistor, and the voltage value of the filter capacitor of the filter circuit is used to determine whether the AC voltage input by the high-voltage generator power supply has a three-phase power phase loss. If the input AC voltage has a phase loss, the voltage value on the filter capacitor will decrease, and the microcontroller can determine whether the input AC voltage has a phase loss fault by judging whether this voltage value is within the normal range according to the pre-stored normal range of voltage. When the phase-loss detection protection circuit detects that the input AC voltage has a phase loss fault, it will send an alarm message to the main control unit 1 through the CAN bus, and at this time, the main control unit 1 will also send a control instruction to the rectifier filter unit 3 through the second CAN interface. At this time, the rectifier and filter unit 3 will no longer send DC voltage to the first inverter unit 4 and the second inverter unit 5, and the main control unit 1 also controls the first signal interface, the second signal interface and the third signal interface to respectively control the first inverter unit 4, the second inverter unit 5 and the high-pressure oil tank 6 to stop running.

[0033] The first inverter unit 4 and the second inverter unit 5 respectively include a microcontroller, a control module, a drive module and a full-bridge inverter circuit; the microcontroller is connected to the second CAN interface of the main control unit 1 through the CAN bus on the one hand, and the microcontroller is connected to the control module on the other hand, the control module is connected to the drive module, the drive module is connected to the input end of the full-bridge inverter circuit, and the output end of the full-bridge inverter circuit is connected to the high-pressure oil tank 6. Among them, the control module can be implemented by a PWM (Pulse Width Modulation) control chip. For example, a PWM control chip with a model number of UC3844 can be used for implementation. The drive module can be implemented by a PWM drive chip. For example, a PWM drive chip with a model number of 2SC0435T can be used for implementation. The full-bridge inverter circuit is composed of an insulated gate bipolar transistor (IGBT), and is an existing full-bridge inverter circuit, and its structure and working principle are not repeated here.

[0034] The user sends the set first high voltage value and the second high voltage value to the microcontroller of the main control unit 1 through the interface unit 2, and the microcontroller of the main control unit 1 sends the set first high voltage value and the second high voltage value to the microcontrollers of the first inverter unit 4 and the second inverter unit 5 respectively. The microcontrollers of the first inverter unit 4 and the second inverter unit 5 set a suitable DC voltage to the reference end of the PWM control chip according to the received first high voltage value and the second high voltage value, so that the PWM control chip determines the square wave duty cycle according to the DC voltage, and controls the PWM drive chip to drive the insulated gate bipolar transistor of the full-bridge inverter circuit, so that the full-bridge inverter circuit generates a high-frequency square wave voltage, and the high-frequency square wave voltage will be respectively input into the high-pressure oil tank 6.

[0035] The control signal regarding when to start and stop the first high voltage value and the second high voltage value output by the high voltage generator power supply can be sent to the first inverter unit 4 and the second inverter unit 5 accordingly after the FPGA of the main control unit 1 parses the timing signal input by the user.

[0036] In the first inverter unit 4 and the second inverter unit 5, in order to prevent the insulated gate bipolar transistor from being damaged by excessive temperature, a heat sink and a temperature detection chip can be installed on the insulated gate bipolar transistor respectively, and the heat sink and the temperature detection chip are respectively connected to the microcontroller of the inverter unit (the first inverter unit 4 and the second inverter unit 5); the temperature of the insulated gate bipolar transistor is detected in real time by the temperature detection chip, and the temperature is converted into a voltage value and sent to the microcontroller of the inverter unit. The microcontroller will perform A / D conversion on the voltage value and compare it with the temperature range of the insulated gate bipolar transistor pre-set in the microcontroller to determine whether the current temperature of the insulated gate bipolar transistor is within a suitable range. If the microcontroller of the inverter unit determines that the current temperature of the insulated gate bipolar transistor exceeds the suitable range, a control signal can be sent to the inverter unit through the microcontroller to stop the inverter unit, that is, the microcontroller does not send a suitable DC voltage to the PWM control chip, so that the PWM control chip cannot determine the square wave duty cycle, thereby making the full-bridge inverter circuit unable to generate a high-frequency square wave voltage.

[0037] In the first inverter unit 4 and the second inverter unit 5, in order to prevent the insulated gate bipolar transistor from being damaged by excessive current, a current transformer can be connected in series in the full-bridge inverter circuit, and the current transformer is connected to the microcontroller of the inverter unit. The detected current of the insulated gate bipolar transistor can be converted into a voltage value through the current transformer, and the voltage value is sent to the microcontroller of the inverter unit. The microcontroller will perform A / D conversion on the voltage value, and compare it with the current range of the insulated gate bipolar transistor preset in the microcontroller to determine whether the current current of the insulated gate bipolar transistor is within the appropriate range. If the microcontroller of the inverter unit determines that the current current of the insulated gate bipolar transistor is overcurrent, a control signal can be sent to the inverter unit through the microcontroller to stop the inverter unit, that is, the microcontroller does not send a suitable DC voltage to the PWM control chip, so that the PWM control chip cannot determine the square wave duty cycle, thereby making the full-bridge inverter circuit unable to generate a high-frequency square wave voltage.

[0038] like Figure 1 and Figure 4 As shown, a first isolation transformer T1, a second isolation transformer T2, an oil tank interface board 7, a first voltage doubling rectifier circuit 8, a second voltage doubling rectifier circuit 9, a microcontroller and an operational amplifier are arranged in the high-voltage oil tank 6; the primary of the first isolation transformer T1 and the second isolation transformer T2, the microcontroller and the operational amplifier are connected to the oil tank interface board 7 respectively, the secondary of the first isolation transformer T1 is connected to the input end of the first voltage doubling rectifier circuit 8, the secondary of the second isolation transformer T2 is connected to the input end of the second voltage doubling rectifier circuit 9, the output end of the first voltage doubling rectifier circuit 8 is connected to the first high-voltage output end of the high-voltage oil tank 6, and the output end of the second voltage doubling rectifier circuit 9 is connected to the second high-voltage output end of the high-voltage oil tank 6; wherein, the second high-voltage output end is connected to the first high-voltage output end on the one hand, and is grounded on the other hand, so that the voltage reference of the second high-voltage value output by the second high-voltage output end is suspended on the first high-voltage value output by the first high-voltage output end, so as to realize that the second high-voltage value output by the second high-voltage output end takes the first high-voltage value output by the first high-voltage output end as a reference point.

[0039] Among them, the oil tank interface board 7 is a transfer board inside and outside the high-pressure oil tank 6. The oil tank interface board 7 is directly pressed on the top of the box body of the high-pressure oil tank 6, and a sealing ring is added to the edge to play a sealing role, and the input and output signals are connected through the terminal block welded on the oil tank interface board 7. Specifically, the terminal block of the oil tank interface board 7 is respectively provided with the input and output ends of the inverter 1, the input and output ends of the inverter 2, the CAN interface end, the signal interface end and the signal feedback end corresponding to the CAN interface end and the signal interface end; wherein, the microcontroller of the high-pressure oil tank 6 is connected to the CAN interface end and the signal feedback end, and the operational amplifier of the high-pressure oil tank 6 is connected to the signal interface end and the signal feedback end. The CAN interface end is connected to the second CAN interface of the main control unit 1 through the CAN bus, and the signal interface end is connected to the third signal interface of the main control unit 1 through the signal cable. The input end of inverter 1 is connected to the output end of the full-bridge inverter circuit of the first inverter unit 4, and the output end of inverter 1 is connected to the primary of the first isolation transformer T1; the input end of inverter 2 is connected to the output end of the full-bridge inverter circuit of the second inverter unit 5, and the output end of inverter 2 is connected to the primary of the second isolation transformer T2, the secondary of the first isolation transformer T1 is connected to the input end of the first voltage doubling rectifier circuit 8, and the secondary of the second isolation transformer T2 is connected to the input end of the second voltage doubling rectifier circuit 9.

[0040] The first voltage doubling rectifier circuit 8 and the second voltage doubling rectifier circuit 9 include at least one rectifier bridge circuit and multiple high-voltage capacitors. The input ends of each rectifier bridge circuit are connected via a high-voltage capacitor, a high-voltage capacitor is connected in parallel between the output ends of each rectifier bridge circuit, and each rectifier bridge circuit is connected in series.

[0041] The first isolation transformer T1 and the second isolation transformer T2 are used to increase the high-frequency square wave voltage generated by the corresponding inverter unit to a preset value (such as 50KV and 5KV respectively), and send the increased high-frequency square wave voltage to the corresponding voltage doubler rectifier circuit for further boosting, rectification and filtering to achieve the output of the first high voltage value and the second high voltage value.

[0042] In order to ensure that the first high voltage value and the second high voltage value output by the high-pressure oil tank 6 meet user needs, a second sampling circuit 10 and a third sampling circuit 11 can be respectively set in the high-pressure oil tank 6, the input end of the second sampling circuit 10 is connected to the output end of the first voltage doubling rectifier circuit 8, the output end of the second sampling circuit 10 is respectively connected to the first high voltage output end and the output end of the third sampling circuit 11, the input end of the third sampling circuit 11 is connected to the output end of the second voltage doubling rectifier circuit 9, and the output end of the third sampling circuit 11 is connected to the second high voltage output end. Among them, the second sampling circuit 10 and the third sampling circuit 11 both include a third sampling resistor and a fourth sampling resistor, one end of the third sampling resistor serves as the input end of the corresponding sampling circuit, the other end of the fourth sampling resistor is connected to one end of the fourth sampling resistor, and the other end of the fourth sampling resistor serves as the output end of the corresponding sampling circuit; and the other end of the third sampling resistor and one end of the fourth sampling resistor are respectively connected to the signal feedback end on the terminal block of the oil tank interface board 7, which is used to send the high voltage output of the detected high-pressure oil tank 6 to the main control unit 1 through the signal interface after amplification by the operational amplifier of the high-pressure oil tank 6, so that the main control unit 1 can realize the closed-loop control of the first high voltage value and the second high voltage value output by the high-voltage generator power supply. In addition, the high-pressure oil tank 6 also sends the state of the high-pressure oil tank 6 to the main control unit 1 in real time through the CAN interface end, so that the main control unit 1 can control the working state of the high-pressure oil tank 6 according to the received state of the high-pressure oil tank 6.

[0043] It should be emphasized that the high-voltage part of the high-voltage oil tank 6 and the low-voltage part of the user system should achieve good electrical insulation to ensure the safety of the user. The following two methods are usually used for electrical insulation isolation: one is to use optical fiber to isolate data communication, and the other is to ensure that the electrical insulation gap and structure meet the requirements in the structural design of the high-voltage oil tank. The high-voltage oil tank is filled with transformer oil, and the electrical insulation performance of transformer oil is significantly higher than that of air. Therefore, the insulation of transformer oil can reduce the insulation requirements for the electrical gap in space, so that the structural design volume of the high-voltage oil tank can be reduced.

[0044] The high-voltage generator power supply provided by the present invention can provide two-way high-voltage output through a main control unit, an interface unit, a rectifier and filter unit, a first inverter unit, a second inverter unit and a high-voltage oil tank. The output high-voltage value can not only be adjusted and set, but also the output second high-voltage value uses the first high-voltage value as a reference potential, so that the high-voltage generator power supply can be directly connected to an X-ray tube controlled by a gate-controlled switch to power it.

[0045] The above is a detailed description of the high voltage generator power supply provided by the present invention. For those skilled in the art, any obvious changes made to it without departing from the essential spirit of the present invention will fall within the protection scope of the patent right of the present invention.

Claims

1. A high voltage generator power supply for connecting to an X-ray tube controlled by a grid-controlled switch to supply power to the tube, characterized in that It includes a main control unit, an interface unit, a rectifying and filtering unit, a first inverter unit, a second inverter unit and a high-voltage oil tank, wherein the main control unit is respectively connected to the interface unit, the rectifying and filtering unit, the first inverter unit, the second inverter unit and the high-voltage oil tank, the input end of the rectifying and filtering unit is connected to an AC voltage, the output end of the rectifying and filtering unit is respectively connected to the input end of the first inverter unit and the second inverter unit, and the output end of the first inverter unit and the second inverter unit is respectively connected to the high-voltage oil tank; wherein, The high-voltage oil tank is provided with a first isolation transformer, a second isolation transformer, an oil tank interface board, a first voltage doubling rectifier circuit, a second voltage doubling rectifier circuit, a microcontroller and an operational amplifier; the primary of the first isolation transformer and the second isolation transformer, the microcontroller and the operational amplifier are respectively connected to the oil tank interface board, the secondary of the first isolation transformer is connected to the input end of the first voltage doubling rectifier circuit, the secondary of the second isolation transformer is connected to the input end of the second voltage doubling rectifier circuit, the output end of the first voltage doubling rectifier circuit is connected to the first high-voltage output end of the high-voltage oil tank, and the output end of the second voltage doubling rectifier circuit is connected to the second high-voltage output end of the high-voltage oil tank; the second high-voltage output end is connected to the first high-voltage output end on the one hand, and is grounded on the other hand, so that the voltage reference of the second high voltage outputted by the second high-voltage output end is suspended on the first high voltage outputted by the first high-voltage output end, so as to realize that the second high voltage outputted by the second high-voltage output end takes the first high voltage outputted by the first high-voltage output end as a reference point; The first isolation transformer and the second isolation transformer are used to increase the high-frequency square wave voltage generated by the corresponding inverter unit to a preset value, and send the increased high-frequency square wave voltage to the corresponding voltage doubler rectifier circuit for further boosting, rectification and filtering to output a first high voltage and a second high voltage; wherein the first high voltage is loaded between the cathode target and the anode target of the X-ray tube; the second high voltage is used to control the output and shutoff of the X-ray tube by the X-ray tube through the grid control circuit of the X-ray tube.

2. The high voltage generator power supply according to claim 1, characterized in that: The main control unit is respectively provided with an operational amplifier, an analog / digital conversion chip, a first CAN interface, a second CAN interface, a first signal interface, a second signal interface and a third signal interface. The input end of the operational amplifier is connected to the high-pressure oil tank, the output end of the operational amplifier is connected to the input end of the analog / digital conversion chip, the output end of the analog / digital conversion chip is connected to the microcontroller of the main control unit, and the microcontroller is respectively connected to the first CAN interface and the second CAN interface; the second CAN interface is respectively connected to the interface unit, the rectifier and filter unit, the first inverter unit, the second inverter unit and the high-pressure oil tank, the first signal interface and the second signal interface are respectively connected to the first inverter unit and the second inverter unit, and the third signal interface is connected to the high-pressure oil tank.

3. The high voltage generator power supply according to claim 1, characterized in that: The rectification and filtering unit includes a three-phase full-bridge rectification circuit, a microcontroller and a filtering circuit. The input end of the three-phase full-bridge rectification circuit is connected to an AC voltage, the output end of the three-phase full-bridge rectification circuit is connected to the input end of the filtering circuit, and the output end of the filtering circuit is respectively connected to the input ends of the first inverter unit and the second inverter unit.

4. The high voltage generator power supply according to claim 3, characterized in that: The rectification and filtering unit is provided with a slow start circuit and a first sampling circuit; the slow start circuit is arranged between the AC voltage and the three-phase full-bridge rectification circuit and is connected to the microcontroller, and the first sampling circuit is respectively connected to the output ends of the microcontroller and the filtering circuit.

5. The high voltage generator power supply according to claim 4, characterized in that: The slow start circuit includes a thermistor, a main relay and an auxiliary relay, one end of the normally open contact of the main relay is connected to one end of the thermistor and each phase of the AC voltage, the other end of the thermistor is connected to one end of the normally open contact of the auxiliary relay, the other ends of the normally open contacts of the main relay and the auxiliary relay are connected to the input end of the three-phase full-bridge rectifier circuit respectively, and the normally open contacts of the main relay and the auxiliary relay are also connected to the microcontroller respectively.

6. The high voltage generator power supply according to claim 3, characterized in that: A phase loss detection protection circuit is provided in the filtering circuit, and the phase loss detection protection circuit includes a voltage comparator, a non-phase input end of the voltage comparator is connected to the first sampling circuit, an inverting input end of the voltage comparator is connected to a reference voltage, and an output end of the voltage comparator is connected to the microcontroller.

7. The high voltage generator power supply according to claim 1, characterized in that: The first inverter unit and the second inverter unit respectively include a microcontroller, a control module, a drive module and a full-bridge inverter circuit; the microcontroller is connected to the main control unit on the one hand, and is connected to the control module on the other hand, the control module is connected to the drive module, the drive module is connected to the input end of the full-bridge inverter circuit, and the output end of the full-bridge inverter circuit is connected to the high-pressure oil tank.

8. The high voltage generator power supply according to claim 7, characterized in that: The full-bridge inverter circuit is provided with a heat sink, a temperature detection chip and a current transformer. The heat sink, the temperature detection chip and the current transformer are respectively connected to the microcontroller of each inverter unit.

9. The high voltage generator power supply according to claim 1, characterized in that: A second sampling circuit and a third sampling circuit are respectively arranged in the high-pressure oil tank, the input end of the second sampling circuit is connected to the output end of the first voltage doubling rectifier circuit, the output end of the second sampling circuit is respectively connected to the first high-voltage output end and the output end of the third sampling circuit, the input end of the third sampling circuit is connected to the output end of the second voltage doubling rectifier circuit, and the output end of the third sampling circuit is connected to the second high-voltage output end; the second sampling circuit and the third sampling circuit are also respectively connected to the oil tank interface board.

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