Circuit topology of a switched magnet power supply

Abstract

This disclosure provides a circuit topology for a switching magnet power supply, used to provide excitation current to a magnet load, which is an inductive load. The circuit topology includes: a first voltage source, a second voltage source, a capacitor, a freewheeling diode, an insulated-gate bipolar transistor (IGBT), a resistor, and a blocking diode. The first voltage source, second voltage source, capacitor, and freewheeling diode are connected in parallel, and the IGBT is connected in series between the capacitor and the freewheeling diode. The voltage of the first voltage source is higher than that of the second voltage source. The first voltage source provides the excitation voltage, and the second voltage source serves as the power source. The first voltage source is connected in series with the resistor, and then in parallel with the series-connected second voltage source and the blocking diode. The capacitor and the freewheeling diode are connected in parallel across the series-connected second voltage source and the blocking diode, respectively. This circuit topology is simple, highly reliable, and has a short control time.

Description

Technical Field

[0001] This disclosure relates to the field of carbon ion therapy technology, and more particularly to a circuit topology for a switching magnet power supply. Background Technology

[0002] In the carbon ion therapy system, the switching magnet power supply provides excitation current to the switching magnet. When it is necessary to cut off the beam, the current value of the switching magnet power supply is required to rise from 0A to more than 300A in a very short time when it receives the enable signal.

[0003] Currently, the switching magnet power supply circuit topology in carbon ion therapy systems is complex, resulting in high hardware costs. Furthermore, the circuit topology requires a certain response time for control, leading to a longer control time. Summary of the Invention

[0004] To address the aforementioned technical problems, this disclosure provides a circuit topology for a switching magnet power supply, which at least partially solves the problems of the prior art.

[0005] Based on this, an embodiment of the present disclosure provides a circuit topology for a switching magnet power supply, used to provide excitation current to a magnet load, the magnet load being an inductive load, including: a first voltage source, a second voltage source, a capacitor, a freewheeling diode, an insulated-gate bipolar transistor, a resistor, and a diode; the first voltage source, the second voltage source, the capacitor, and the freewheeling diode are connected in parallel, and the insulated-gate bipolar transistor is connected in series between the capacitor and the freewheeling diode, wherein the voltage of the first voltage source is higher than the voltage of the second voltage source, the first voltage source is used to provide excitation voltage, the second voltage source is used as a power source, the first voltage source is connected in series with the resistor, and then connected in parallel with the series-connected second voltage source and the blocking diode, and the capacitor and the freewheeling diode are respectively connected in parallel across the series-connected second voltage source and the blocking diode.

[0006] According to embodiments of this disclosure, when the insulated gate bipolar transistor is in the on state, the first voltage source and the capacitor simultaneously provide excitation current to the magnetic load.

[0007] According to embodiments of this disclosure, when the insulated gate bipolar transistor is in the off state, the magnetic load and the freewheeling diode form a circuit, consuming the energy stored in the magnetic load.

[0008] According to an embodiment of this disclosure, when the voltage of the capacitor drops to the voltage of the second voltage source, the second voltage source provides excitation current to the magnetic load.

[0009] According to embodiments of this disclosure, the capacitance value of the capacitor is 45uF to 55uF, and the withstand voltage is not less than 2000V.

[0010] According to embodiments of this disclosure, the first voltage source and the second voltage source are DC voltage sources.

[0011] According to embodiments of this disclosure, the voltage value of the first voltage source is 1450V to 1550V, and the voltage value of the second voltage source is 11V to 13V.

[0012] According to embodiments of this disclosure, the resistance value is 1450Ω to 1550Ω.

[0013] The circuit topology of the switching magnet power supply provided in the embodiments of this disclosure has at least the following beneficial effects:

[0014] The circuit topology adopts a buck converter circuit with two voltage sources connected in parallel: one is a high voltage source that provides the excitation voltage, and the other is a low voltage source that serves as the power source when operating at 300A DC. This greatly reduces the number of hardware components, thereby effectively reducing the failure rate, improving reliability, reducing hardware costs, and compressing the space required.

[0015] Furthermore, this circuit topology only requires the insulated gate bipolar transistor to provide the corresponding level signal, and the voltage source can complete the corresponding output without the need for self-control adjustment, which greatly shortens the control time and control difficulty. Attached Figure Description

[0016] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0017] Figure 1 The circuit diagram schematically illustrates the circuit topology of a conventional carbon ion therapy system power supply device.

[0018] Figure 2 A circuit diagram schematically illustrates the circuit topology of a switching magnet power supply according to an embodiment of the present disclosure. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0020] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0021] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0022] In the description of this disclosure, it should be understood that the terms "longitudinal", "length", "circumferential", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the subsystem or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0023] Throughout the accompanying drawings, identical elements are represented by the same or similar reference numerals. Conventional structures or constructions have been omitted where they may cause confusion in understanding this disclosure. Furthermore, the shapes, dimensions, and positional relationships of the components in the drawings do not reflect actual size, scale, or actual positional relationships. Additionally, any reference numerals placed between parentheses in the claims should not be construed as limiting the claims.

[0024] Similarly, to simplify this disclosure and aid in understanding one or more of the various aspects of the disclosure, in the above description of exemplary embodiments of the present disclosure, various features of the present disclosure are sometimes grouped together in a single embodiment, figure, or description thereof. The use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present disclosure. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] In realizing the present invention, the applicant found that the circuit topology of conventional carbon ion therapy power supply devices is complex.

[0027] Figure 1 The circuit diagram schematically illustrates the circuit topology of a conventional carbon ion therapy system power supply device.

[0028] like Figure 1 As shown, the circuit topology of the power supply device in a traditional carbon ion therapy system consists of four H-bridges connected in series. Each H-bridge requires a DC voltage source, several insulated-gate bipolar transistors (IGBTs), and several diodes, making the entire control circuit complex. After receiving a voltage signal, the voltage source performs proportional-integral (PI) self-control adjustment according to a preset current value, outputting a corresponding pulse-width modulation (PWM) wave to each IGBT to ultimately complete the current output. However, PI self-control adjustment requires a certain response time, resulting in a long control time for the circuit topology.

[0029] In view of this, the present disclosure provides a circuit topology that uses a very small amount of hardware to control the excitation current of the switching magnet in a shorter time.

[0030] Figure 2 A circuit diagram illustrating the circuit topology of a switching magnet power supply according to an embodiment of the present disclosure is shown schematically.

[0031] like Figure 2 As shown, this circuit topology is used to provide excitation current for a magnetic load LOAD, which is an inductive load. The circuit topology may include, for example, a first voltage source DC1, a second voltage source DC2, a capacitor C1, a freewheeling diode D2, an insulated gate bipolar transistor VT, a resistor R1, and a blocking diode D1.

[0032] A first voltage source DC1, a second voltage source DC2, a capacitor C1, and a freewheeling diode D2 are connected in parallel. An insulated-gate bipolar transistor VT is connected in series between capacitor C1 and freewheeling diode D2. The voltage of the first voltage source D1 is higher than the voltage of the second voltage source DC2. In other words, the first voltage source DC1 uses a high-voltage power supply to provide the excitation voltage, while the second voltage source DC2 uses a low-voltage power supply as a power source.

[0033] The first voltage source DC1 is connected in series with the resistor R1, and then in parallel with the second voltage source DC2 and the blocking diode D1. The capacitor C1 and the freewheeling diode D2 are connected in parallel across the second voltage source DC2 and the blocking diode D1, respectively.

[0034] The blocking diode D1 can prevent a high voltage source from breaking down a low voltage source.

[0035] Resistor R1 acts as a current-limiting resistor, primarily limiting the output current of the first voltage source DC1 during platform current output, in order to match a high-voltage power source of appropriate power. The selection of resistor R1 is also influenced by the capacitance value.

[0036] According to embodiments of this disclosure, when the insulated-gate bipolar transistor VT is in the on-state, the first voltage source DC1 and capacitor C1 simultaneously provide excitation current to the magnetic load LOAD. When the voltage of capacitor C1 drops to the voltage value of the second voltage source DC2, the second voltage source DC2 begins to provide excitation current to the magnetic load. When the insulated-gate bipolar transistor VT is in the off-state, the magnetic load LOAD and the freewheeling diode D2 form a circuit, consuming the energy stored in the magnetic load LOAD.

[0037] As an optional implementation, the first voltage source DC1 and the second voltage source DC2 are DC voltage sources. The voltage value of the first voltage source DC1 can be 1450V to 1550V, preferably 1500V. The first voltage source DC1 stores energy in capacitor C1, ensuring that capacitor C1 has a high voltage to store energy, guaranteeing that the current rises to over 300A within a short time (e.g., within 5ms). The voltage value of the second voltage source is 11V to 13V, preferably 12V, and it serves as the main power source during DC operation.

[0038] As an alternative implementation, since an excessively large capacitance value would result in an excessively long charging time and a long overcharge current duration, the capacitance value of the capacitor can be 45uF to 55uF, and the withstand voltage value should not be less than 2000V.

[0039] As an optional implementation, the resistance of resistor R1 is 1450Ω to 1550Ω, preferably 1500Ω.

[0040] The working principle of the above circuit topology is as follows:

[0041] Upon receiving the power-on signal, a voltage drive signal is applied to the insulated-gate bipolar transistor (IGBT) VT, turning it on. Initially, since the first voltage source DC1 has already charged capacitor C1 to a high voltage, both DC1 and C1 simultaneously provide excitation current to the load magnet LOAD, resulting in a significant current rise. Due to the effect of resistor R1, the energy consumed by the load magnet LOAD exceeds the energy provided by the first voltage source DC1, causing the voltage of capacitor C1 to continuously decrease as the current continues to rise. However, once the current reaches 300A, the voltage across capacitor C1 continues to decrease until it equals the voltage of the second voltage source DC2. The excitation current for the load magnet LOAD is then primarily provided by the second voltage source DC2, maintaining a current value of approximately 300A while the voltage across capacitor C1 remains constant. When the power supply receives the current-stop signal, it directly changes the drive voltage of the IGBT VT to 0V, turning it off. The circuit consisting of the second voltage source DC2 and the load magnet LOAD then consumes the energy stored in the magnet. Afterward, the first voltage source DC1 begins charging capacitor C1.

[0042] The circuit topology provided in this embodiment reduces the number of power source components by two compared to traditional circuit topologies, reduces the capacity of the capacitor assembly to less than one-thousandth of the original, and reduces the number of insulated gate bipolar transistors (VTs) to one-eighth of the original.

[0043] In summary, this circuit topology employs a buck converter circuit, using only two voltage sources connected in parallel: one high-voltage source providing the excitation voltage, and the other a low-voltage source serving as the power source during DC 300A operation. This significantly reduces the number of hardware components, effectively lowering the failure rate and improving reliability, while also reducing hardware costs and compressing space. Furthermore, this circuit topology only requires a corresponding level signal to the insulated-gate bipolar transistor (IGBT) for the voltage source to complete the corresponding output, eliminating the need for self-regulation and greatly shortening control time.

[0044] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A circuit topology for a switching magnet power supply, used to provide excitation current to a magnetic load, wherein the magnetic load is an inductive load, characterized in that, include: First voltage source, second voltage source, capacitor, freewheeling diode, insulated gate bipolar transistor, resistor and blocking diode; The first voltage source, the second voltage source, the capacitor, and the freewheeling diode are connected in parallel, and the insulated gate bipolar transistor is connected in series between the capacitor and the freewheeling diode. The voltage of the first voltage source is higher than the voltage of the second voltage source. The first voltage source is used to provide excitation voltage, and the second voltage source is used as a power source. The first voltage source is connected in series with the resistor, and then in parallel with the second voltage source connected in series and the blocking diode. The capacitor and the freewheeling diode are respectively connected in parallel across the second voltage source and the blocking diode connected in series.

2. The circuit topology according to claim 1, characterized in that, When the insulated gate bipolar transistor is in the on state, the first voltage source and the capacitor simultaneously provide excitation current to the magnetic load.

3. The circuit topology according to claim 1, characterized in that, When the voltage of the capacitor drops to the voltage of the second voltage source, the second voltage source provides excitation current to the magnetic load.

4. The circuit topology according to claim 1, characterized in that, When the insulated gate bipolar transistor is in the off state, the magnetic load and the freewheeling diode form a circuit, consuming the energy stored in the magnetic load.

5. The circuit topology according to claim 1, characterized in that, The capacitance of the capacitor is 45uF to 55uF, and the withstand voltage is not less than 2000V.

6. The circuit topology according to claim 1, characterized in that, The first voltage source and the second voltage source are DC voltage sources.

7. The circuit topology according to claim 6, characterized in that, The voltage value of the first voltage source is 1450V to 1550V, and the voltage value of the second voltage source is 11V to 13V.

8. The circuit topology according to claim 1, characterized in that, The resistance value of the resistor is 1450Ω to 1550Ω.

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