CN-116406069-B - Filament power supply and radiotherapy equipment

Abstract

The application relates to a filament power supply and radiotherapy equipment. The filament power supply comprises an input end of an inverter circuit, an output end of the inverter circuit, a driving end of an adjusting circuit and a driving end of the inverter circuit, wherein the input end of the inverter circuit is connected with a direct current power supply, the output end of the inverter circuit is connected with a magnetron and is used for converting direct current into alternating current and providing electric energy for the magnetron by utilizing the alternating current, the input end of the adjusting circuit is connected with the output end of the inverter circuit, the output end of the adjusting circuit is connected with the driving end of the inverter circuit and is used for obtaining electric parameters output by the inverter circuit and generating driving signals according to the electric parameters and given electric parameters, and the driving signals are used for adjusting the electric parameters output by the inverter circuit. The output electric parameters of the inverter circuit are obtained through the setting adjusting circuit, the driving signal is generated, and the electric parameters output by the inverter circuit are adjusted through the driving signal. The electric parameters output by the inverter circuit can be accurately adjusted to given electric parameters required by the current use scene, the temperature of a cathode filament in the magnetron can be ensured, and the service life of the magnetron can be further prolonged.

Inventors

• GONG XIGUO

Assignees

• 上海联影医疗科技股份有限公司

Dates

Publication Date

20260505

Application Date

20191227

Claims (8)

1. 1. The filament power supply is characterized by comprising an inverter circuit, a regulating circuit and a voltage protection circuit; the input end of the inverter circuit is connected with a direct current power supply, the output end of the inverter circuit is connected with a magnetron and used for converting direct current into alternating current and providing electric energy for the magnetron by utilizing the alternating current; the input end of the adjusting circuit is connected with the output end of the inverter circuit, the output end of the adjusting circuit is connected with the driving end of the inverter circuit and is used for acquiring the electric parameters output by the inverter circuit and generating driving signals according to the electric parameters and given electric parameters, and the driving signals are used for adjusting the electric parameters output by the inverter circuit; The voltage protection circuit is connected between the inverter circuit and the magnetron and is used for protecting the voltage of the filament power supply; The inverter circuit further comprises a sampling resistor, wherein the sampling resistor is arranged at the output end of the inverter unit; the adjusting circuit further comprises a power calculating unit, a first analog-to-digital conversion unit, a first comparison unit and an adjusting unit, wherein the input end of the power calculating unit is connected with the input end of the magnetron, the output end of the power calculating unit is connected with the second input end of the first comparison unit, and the adjusting circuit is used for acquiring pulse parameters input into the magnetron, obtaining a given current signal according to the pulse parameters and transmitting the given current signal to the first comparison unit; The input end of the first analog-to-digital conversion unit is connected with the sampling resistor, the output end of the first analog-to-digital conversion unit is connected with the first input end of the first comparison unit, and the first analog-to-digital conversion unit is used for collecting the current output by the inverter circuit through the sampling resistor and performing analog-to-digital conversion on the current to obtain a digital current signal; The second input end of the first comparison unit is connected with a given current signal, and the output end of the first comparison unit is connected with the adjusting unit and is used for comparing the digital current signal with the given current signal to obtain a first error signal; The output end of the adjusting unit is connected with the inversion unit and is used for generating a driving signal according to the first error signal and transmitting the driving signal to the inversion unit.
2. 2. The filament power supply according to claim 1, wherein an input end of the inversion unit is connected to a dc power supply for converting dc power into ac power; The input end of the regulating circuit is connected with the sampling resistor, the output end of the regulating circuit is connected with the inversion unit, the regulating circuit collects the current output by the inversion circuit through the sampling resistor, generates a driving signal according to the current and a given current, and transmits the driving signal to the inversion unit.
3. 3. The filament power supply of claim 1, wherein the adjustment unit comprises a proportional integral adjustment unit and a pulse width modulation unit; The input end of the proportional-integral regulating unit is connected with the output end of the first comparing unit, and the output end of the proportional-integral regulating unit is connected with the input end of the pulse width modulating unit and is used for carrying out proportional-integral regulation on the first error signal to obtain a regulating signal; the output end of the pulse width modulation unit is connected with the inversion unit and is used for carrying out pulse width modulation on the adjusting signal to obtain a driving signal and transmitting the driving signal to the inversion unit.
4. 4. The filament power supply of claim 3, wherein the pulse parameters include pulse peak voltage, pulse peak current, pulse width, and pulse repetition frequency; The power calculation unit is also used for obtaining average power according to the pulse peak voltage, the pulse peak current, the pulse width and the pulse repetition frequency, and searching a mapping table of power and current according to the average power to obtain a given current signal.
5. 5. The filament power supply of claim 4, wherein the conditioning circuit further comprises a second analog-to-digital conversion unit and a second comparison unit; The input end of the second analog-to-digital conversion unit is connected with the output end of the inverter circuit, and the output end of the second analog-to-digital conversion unit is connected with the first input end of the second comparison unit; the second input end of the second comparison unit is connected with the output end of the proportional-integral regulating unit, the output end of the second comparison unit is connected with the input end of the pulse width modulation unit, and the second comparison unit is used for comparing the regulating signal with the digital voltage signal to obtain a second error signal and transmitting the second error signal to the pulse width modulation unit.
6. 6. The filament power supply of claim 1, wherein the voltage protection circuit comprises a first inductance and a second inductance; the output positive electrode of the inverter circuit is connected with the filament of the magnetron through a first inductor; And the output negative electrode of the inverter circuit is connected with the cathode of the magnetron through a second inductor.
7. 7. The filament power supply of claim 5, wherein the voltage protection circuit further comprises a diode, a first capacitor, and a second capacitor; the diode and the first capacitor are connected in parallel between an output positive electrode and an output negative electrode of the inverter circuit; The second capacitor is connected between a filament input and a cathode input of the magnetron.
8. 8. A radiotherapy apparatus comprising the filament power supply of any one of claims 1 to 7.

Description

Filament power supply and radiotherapy equipment The application relates to a split application of '201911375564.2 for application number, 2019, 12, 27 for application date, namely a filament power supply and radiotherapy equipment'. Technical Field The application relates to the technical field of medical equipment, in particular to a filament power supply and radiotherapy equipment. Background The medical electron linear accelerator is an accelerating device which accelerates electrons by utilizing a microwave electromagnetic field and has a linear motion orbit, and is used for the radiotherapy of tumors or other focus of a patient. It can generate high-energy X-ray and electron beam, and has the features of high dosage rate, short irradiation time, large irradiation field, high dosage uniformity and stability, small penumbra area, etc. In the current medical electron linear accelerator in the prior art, a filament power supply supplies power to a magnetron. The larger the current supplied by the filament power supply to the magnetron, the higher the temperature of the magnetron cathode filament, and the smaller the current supplied by the filament power supply to the magnetron, the lower the temperature of the magnetron cathode filament. And the lifetime of the magnetron is closely related to the temperature of the cathode filament. To achieve maximum lifetime, the cathode filament of the magnetron must be operated at the correct temperature. Too low a temperature results in unstable operation of the magnetron due to reduction of emission of X-rays or electron rays, further damage of the magnetron, and too high a temperature results in rapid deterioration of the cathode, resulting in shortened life of the magnetron. The prior art cannot precisely control the current supplied from the filament power supply to the magnetron, thereby shortening the life of the magnetron. Disclosure of Invention In view of the foregoing, it is desirable to provide a filament power supply and a radiotherapy apparatus that can improve the service life of a magnetron. The filament power supply comprises an inverter circuit and an adjusting circuit, wherein the input end of the inverter circuit is connected with a direct current power supply, the output end of the inverter circuit is connected with a magnetron and used for converting direct current into alternating current and providing electric energy for the magnetron by utilizing the alternating current, the input end of the adjusting circuit is connected with the output end of the inverter circuit, the output end of the adjusting circuit is connected with the driving end of the inverter circuit and used for obtaining electric parameters output by the inverter circuit and generating driving signals according to the electric parameters and given electric parameters, and the driving signals are used for adjusting the electric parameters output by the inverter circuit. In one embodiment, the inverter circuit further comprises an inverter unit and a sampling resistor, wherein the input end of the inverter unit is connected with a direct current power supply and used for converting direct current into alternating current, the filtering unit is arranged at the output end of the inverter unit and used for conducting filtering processing on the alternating current, the sampling resistor is arranged at the output end of the inverter unit, the input end of the adjusting circuit is connected with the sampling resistor, the output end of the adjusting circuit is connected with the inverter unit, the adjusting circuit collects current output by the inverter circuit through the sampling resistor and generates a driving signal according to the current and a given current, and the driving signal is transmitted to the inverter unit. In one embodiment, the adjusting circuit comprises a first analog-to-digital conversion unit, a first comparison unit and an adjusting unit, wherein the input end of the first analog-to-digital conversion unit is connected with the sampling resistor, the output end of the first analog-to-digital conversion unit is connected with the first input end of the first comparison unit and is used for collecting current output by the inverter circuit through the sampling resistor and performing analog-to-digital conversion on the current to obtain a digital current signal, the second input end of the first comparison unit is connected with a given current signal, the output end of the first comparison unit is connected with the adjusting unit and is used for comparing the digital current signal with the given current signal to obtain a first error signal, and the output end of the adjusting unit is connected with the inverter unit and is used for generating a driving signal according to the first error signal and transmitting the driving signal to the inverter unit. In one embodiment, the adjusting unit comprises a proportional integral adjusting unit and a pulse width mod