A nuclear reactor modular rod control power supply

Abstract

The application discloses a nuclear reactor modular rod control power supply, and relates to the field of reactor fuel control. The application designs a main power phase-displaced parallel circuit to output time sequence control current to a driving coil. The main power phase-displaced parallel circuit is a four-phase circuit. A first phase is a master machine, and the remaining three phases are slave machines. The master machine is in parallel connection with the slave machines. The application adopts the four-phase phase-displaced parallel circuit. The control mode of each phase circuit is master-slave current sharing. Compared with the prior art which uses one IGBT chopper output, the four-phase circuit of the application shares current stress and voltage, uniformly distributes all power losses on all phase circuits, makes the loss of each phase element smaller, relieves the voltage applied to the switch tube by the circuit, thereby reducing the loss of the switch tube, and improving the electromagnetic compatibility and stability of the power supply.

Description

Technical Field

[0001] This invention relates to the field of reactor fuel control, and in particular to a modular rod-controlled power supply for nuclear reactors. Background Technology

[0002] The fuel control rod drive mechanism is the only brakeable device unit within the reactor pressure vessel and serves as the actuator for the reactor control and nuclear safety protection system. The reactor relies on the fuel control rod drive mechanism to pull the control rods to achieve reactor startup, power regulation, reactivity compensation, and safe shutdown. Nuclear power plants employ a magnetic lifting drive mechanism that uses coil energization to actuate the control rods. The control rods move in steps by the alternating action of three sets of coils within the drive mechanism; each step requires close coordination between the three sets of coils and the chuck.

[0003] The control rod power supply is the power source for the fuel control rod drive mechanism in a nuclear power plant reactor. The safe and reliable operation of the control rod power supply is crucial to ensuring the correct execution of the drive mechanism's actions. Currently, control rod power supply systems primarily utilize switching power supply technology based on Insulated Gate Bipolar Transistors (IGBTs). To improve integration, several DC chopper modules in the control rod power supply cabinet share a single rectifier module. This results in an excessively long DC bus, significantly increasing its inductance. This limits the operating frequency of the chopper module, increases the current stress on the switching transistors, causes voltage overshoot applied to the switching transistors, and ultimately leads to increased switching transistor losses. Summary of the Invention

[0004] The purpose of this invention is to provide a modular rod-controlled power supply for nuclear reactors, which can solve the technical problem of increased switching tube losses.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A modular rod-controlled power supply for a nuclear reactor, comprising:

[0007] The main power phase-shifting parallel circuit is used to output timing-controlled current to the drive coil and drive the drive coil. The main power phase-shifting parallel circuit is a four-phase circuit, with the first phase being the master and the remaining three phases being the slave. The master and the slave are connected in parallel.

[0008] Optional features also include: a three-phase full-wave rectifier and filter capacitors;

[0009] The three-phase full-wave rectifier is used to perform full-wave rectification on the input voltage, converting the input voltage from alternating current to direct current, and obtaining the rectified input voltage.

[0010] The filter capacitor is connected to the three-phase full-wave rectifier and the main power phase-shifting parallel circuit, respectively, and is used to filter the rectified input voltage to obtain a rectified and filtered input voltage, which is used as the input voltage of the main power phase-shifting parallel circuit.

[0011] Optionally, the host specifically includes: a power supply output module, a timing control module, and a short-circuit protection module;

[0012] The power supply output module specifically includes: a step-down chopper circuit, a resistor-capacitor absorption circuit, a first capacitor, and an energy release diode;

[0013] The buck chopper circuit includes a first switching transistor and a freewheeling diode. The drain of the first switching transistor is connected to the positive terminal of the input voltage and the cathode of the energy release diode. The source of the first switching transistor is connected to the cathode of the freewheeling diode, the first terminal of the first capacitor, and the short-circuit protection module. The anode of the freewheeling diode is connected to the negative terminal of the input voltage and the timing control module. The cathode of the freewheeling diode is connected to the first terminal of the first capacitor and the short-circuit protection module.

[0014] The RC snubber circuit includes a snubber resistor and a snubber capacitor. The first terminal of the snubber capacitor is connected to the positive terminal of the input voltage, the cathode of the energy release diode, and the drain of the first switching transistor. The second terminal of the snubber capacitor is connected to the first terminal of the snubber resistor. The second terminal of the snubber resistor is connected to the source of the first switching transistor, the first terminal of the first capacitor, the cathode of the freewheeling diode, and the short-circuit protection module. The RC snubber circuit is used to suppress the voltage surge generated when the first switching transistor is turned off. When the first switching transistor is turned off, the snubber capacitor generates a parasitic inductance and charges the parasitic capacitance of the first switching transistor, and the snubber resistor charges the snubber capacitor.

[0015] The cathode of the energy release diode is connected to the positive terminal of the input voltage, and the anode of the energy release diode is connected to the second terminal of the first capacitor, the short-circuit protection module, the timing control module, and the negative terminal of the input voltage. When the second switch is turned off, the energy release diode, together with the freewheeling diode and the filter capacitor, forms a freewheeling circuit. The drive coil generates an inductor current and charges the filter capacitor through the freewheeling circuit.

[0016] The first terminal of the first capacitor is also connected to the short-circuit protection module, and the second terminal of the first capacitor is also connected to the short-circuit protection module, the timing control module, and the negative terminal of the input voltage, respectively.

[0017] The timing control module specifically includes: a second switching transistor, a second capacitor, and a first resistor;

[0018] The drain of the second switching transistor is connected to the anode of the energy release diode, the second terminal of the first capacitor, the short-circuit protection module, and the anode of the freewheeling diode, respectively. The source of the second switching transistor is connected to the negative terminal of the input voltage. The second switching transistor is used to control the timing of the output current and output the current of the control timing.

[0019] The first terminal of the second capacitor is connected to the second terminal of the first resistor. The second terminal of the second capacitor is connected to the source of the second switching transistor and the negative terminal of the input voltage. The first terminal of the first resistor is connected to the drain of the second switching transistor, the anode of the energy release diode, the second terminal of the first capacitor, the short-circuit protection module, and the anode of the freewheeling diode.

[0020] The short-circuit protection module specifically includes: a short-circuit protection diode, a third capacitor, and a first inductor;

[0021] The anode of the short-circuit protection diode is connected to the second terminal of the first inductor, and the cathode of the short-circuit protection diode is connected to the first terminal of the third capacitor. The first terminal of the first inductor is connected to the second terminal of the absorption resistor, the source of the first switching transistor, the first terminal of the first capacitor, and the cathode of the freewheeling diode. The second terminal of the third capacitor is connected to the anode of the energy release diode, the second terminal of the first capacitor, the anode of the freewheeling diode, the first terminal of the first resistor, and the drain of the second switching transistor. The short-circuit protection diode is used to disconnect the connection with the remaining phase circuits when a short-circuit fault occurs in the phase circuit in which the short-circuit protection diode is located.

[0022] Optionally, the slave device specifically includes: a power supply output module and a short-circuit protection module;

[0023] The power supply output module and the short-circuit protection module of the slave device are the same as those of the power supply output module and the short-circuit protection module of the master device.

[0024] Optionally, it may also include: voltage and current detection circuit;

[0025] The voltage and current detection circuit is connected to each phase of the main power phase-shifted parallel circuit to detect the current and voltage of each phase circuit and obtain analog voltage and current quantities; the analog voltage and current quantities include analog voltage quantities and analog current quantities.

[0026] Optionally, it may also include: a digital signal processor;

[0027] The digital signal processor is connected to the voltage and current detection circuit and is used to receive the analog voltage and current quantities and convert them into digital voltage and current quantities, and output pulses according to the digital voltage and current quantities; the digital voltage and current quantities include digital voltage quantities and digital current quantities.

[0028] Optionally, the digital signal processor specifically includes: a pulse width modulator;

[0029] The pulse width modulator is used to adjust the phase of the pulse so that the phase difference between each phase of the main power out-of-phase parallel circuit is 90°.

[0030] Optionally, it may also include: drive and protection circuitry;

[0031] The driving and protection circuits are respectively connected to the digital signal processor and the main power phase-shifting parallel circuit, and are used to receive the pulses, drive the first switch and the second switch to close and open, and isolate the main power phase-shifting parallel circuit and the digital signal processor.

[0032] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0033] This invention discloses a modular rod-controlled power supply for nuclear reactors. The main power staggered-phase parallel circuit outputs a timing-controlled current to the drive coil. This circuit is a four-phase circuit, with the first phase acting as the master and the remaining three phases as slaves, connected in parallel. This invention employs a four-phase staggered-phase parallel circuit, controlling each phase circuit with a master-slave current sharing method. Compared to existing technologies using a single IGBT chopper output, this invention's four-phase circuit evenly distributes current stress and voltage, uniformly distributing all power losses across all phases. This results in lower losses on each phase component, reducing the voltage applied to the switching transistors and thus lowering their losses, improving the power supply's electromagnetic compatibility and stability. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 A flowchart of a modular rod-controlled power supply for a nuclear reactor provided by the present invention;

[0036] Figure 2The circuit diagram of a voltage detection sensor for a modular rod-controlled power supply voltage and current detection circuit for a nuclear reactor provided by the present invention;

[0037] Figure 3 The circuit diagram of the current detection sensor of the modular rod-controlled power supply voltage and current detection circuit for a nuclear reactor provided by the present invention.

[0038] Figure 4 The circuit topology of a modular rod-controlled power supply for a nuclear reactor provided by the present invention is shown below.

[0039] Figure 5 Phase diagram of a four-phase circuit for a modular rod-controlled power supply for a nuclear reactor provided by the present invention;

[0040] Figure 6 Simulation waveforms of three-phase current and total current of a four-phase circuit of a modular rod-controlled power supply for a nuclear reactor provided by the present invention.

[0041] Figure 7 This is a prototype diagram of a modular rod-controlled power supply for a nuclear reactor provided by the present invention;

[0042] Figure 8 The current waveform diagram of a four-phase circuit of a modular rod-controlled power supply for a nuclear reactor provided by the present invention;

[0043] Figure 9 The voltage waveform diagram of a modular rod-controlled power switch for a nuclear reactor when it is switched on and off, as provided by the present invention.

[0044] Symbol explanation:

[0045] Absorption capacitor—1, absorption resistor—2, first switching transistor—3, energy release diode—4, first capacitor—5, freewheeling diode—6, second switching transistor—7, second capacitor—8, first resistor—9, first inductor—10, short-circuit protection diode—11, third capacitor—12, drive coil—13. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] The purpose of this invention is to provide a modular rod-controlled power supply for nuclear reactors. By adopting a four-phase staggered parallel circuit, the control method of each phase circuit is master-slave current sharing, which evenly distributes current stress and voltage, and evenly distributes all power losses on all phases, making the losses on each phase component smaller, alleviating the voltage applied to the switching transistors by the circuit, thereby reducing the losses of the switching transistors.

[0048] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] like Figure 1 As shown, the present invention provides a modular rod-controlled power supply for a nuclear reactor, comprising: a main power phase-shifting parallel circuit for outputting timing-controlled current to a drive coil 13 and driving the drive coil 13, wherein the main power phase-shifting parallel circuit is a four-phase circuit, the first phase is the master phase, and the remaining three phases are slave phases, and the master phase and the slave phase are connected in parallel.

[0050] In practical applications, it also includes: a three-phase full-wave rectifier and a filter capacitor; the three-phase full-wave rectifier is used to perform full-wave rectification on the input voltage, converting the input voltage from AC to DC to obtain the rectified input voltage; the filter capacitor is connected to the three-phase full-wave rectifier and the main power phase-shifting parallel circuit respectively, and is used to filter the rectified input voltage to obtain the rectified and filtered input voltage, which serves as the input voltage of the main power phase-shifting parallel circuit.

[0051] The input voltage is a three-phase 260V AC power. The input voltage is rectified by a three-phase full-wave rectifier and then filtered by a filter capacitor to serve as the bus voltage of the main power phase-shifted parallel circuit. The main power circuit outputs a timing-controlled current to power the drive coil 13.

[0052] The voltage and current detection circuit measures the real-time output current and voltage, and sends the data to the digital signal processor (DSP) for processing. The data is compared with the preset expected value to form an error signal, which sends pulses to the drive and protection circuit, thus forming a digital closed-loop regulation circuit, making the current of the drive coil 13 linearly adjustable.

[0053] The function of a three-phase full-wave rectifier is to convert AC power to DC power. Since the input of a three-phase full-wave rectifier is a three-phase 260V AC circuit, connecting a filter capacitor to the output of the rectifier makes the DC voltage smoother, and this DC voltage serves as the input to the main power staggered parallel circuit. Full-wave rectification is a circuit that rectifies AC power. In one half-cycle of the rectifier circuit, current flows through one rectifier device, such as a crystal diode, while in the other half-cycle, current flows through a second rectifier device. The connection of the two rectifier devices ensures that the current flowing through them flows through the load in the same direction.

[0054] Figure 4 The diagram shows the topology of a main power staggered parallel circuit for a modular rod-controlled power supply for a nuclear reactor provided by this invention. In practical applications, the main unit specifically includes: a power supply output module, a timing control module, and a short-circuit protection module. Figure 4 In the circuit diagram shown, if there is no solid black dot between the intersecting lines, it means that there is no connection between the two lines.

[0055] The power output module specifically includes: a buck chopper circuit, an RC snubber circuit, a first capacitor 5, and an energy release diode 4; the buck chopper circuit includes a first switching transistor 3 and a freewheeling diode 6. The drain of the first switching transistor 3 is connected to the positive terminal of the input voltage and the cathode of the energy release diode 4, respectively. The source of the first switching transistor 3 is connected to the cathode of the freewheeling diode 6, the first terminal of the first capacitor 5, and the short-circuit protection module, respectively. The anode of the freewheeling diode 6 is connected to the negative terminal of the input voltage and the timing control module, respectively. The cathode of the freewheeling diode 6 is connected to the first terminal of the first capacitor 5 and the short-circuit protection module, respectively. The RC snubber circuit includes a snubber resistor 2 and a snubber capacitor 1. The first terminal of the snubber capacitor 1 is connected to the positive terminal of the input voltage, the cathode of the energy release diode 4, and the drain of the first switching transistor 3, respectively. The second terminal of the snubber capacitor 1 is connected to the first terminal of the snubber resistor 2, and the second terminal of the snubber resistor 2 is connected to the source of the first switching transistor 3, the cathode of the first capacitor 5, the cathode of the first capacitor 5, and the drain of the first switching transistor 3, respectively. The first terminal of the first capacitor 5, the cathode of the freewheeling diode 6, and the short-circuit protection module are connected. The RC absorption circuit is used to suppress the voltage surge generated when the first switch 3 is turned off. When the first switch 3 is turned off, the absorption capacitor 1 generates parasitic inductance and charges the parasitic capacitance of the first switch 3. The absorption resistor 2 charges the absorption capacitor 1. The cathode of the energy release diode 4 is connected to the anode of the input voltage. The anode of the energy release diode 4 is connected to the second terminal of the first capacitor 5, the short-circuit protection module, the timing control module, and the negative terminal of the input voltage. When the second switch 7 is turned off, the energy release diode 4, together with the freewheeling diode 6 and the filter capacitor, forms a freewheeling circuit. The drive coil 13 generates inductance current and charges the filter capacitor through the freewheeling circuit. The first terminal of the first capacitor 5 is also connected to the short-circuit protection module. The second terminal of the first capacitor 5 is also connected to the short-circuit protection module, the timing control module, and the negative terminal of the input voltage.

[0056] The timing control module specifically includes: a second switch 7, a second capacitor 8, and a first resistor 9; the drain of the second switch 7 is connected to the anode of the energy release diode 4, the second terminal of the first capacitor 5, the short-circuit protection module, and the anode of the freewheeling diode 6, respectively; the source of the second switch 7 is connected to the negative terminal of the input voltage; the second switch 7 is used to control the timing of the output current and output the current controlling the timing; the first terminal of the second capacitor 8 is connected to the second terminal of the first resistor 9; the second terminal of the second capacitor 8 is connected to the source of the second switch 7 and the negative terminal of the input voltage, respectively; the first terminal of the first resistor 9 is connected to the drain of the second switch 7, the anode of the energy release diode 4, the second terminal of the first capacitor 5, the short-circuit protection module, and the anode of the freewheeling diode 6, respectively.

[0057] The short-circuit protection module specifically includes: a short-circuit protection diode 11, a third capacitor 12, and a first inductor 10; the anode of the short-circuit protection diode 11 is connected to the second terminal of the first inductor 10, the cathode of the short-circuit protection diode 11 is connected to the first terminal of the third capacitor 12, the first terminal of the first inductor 10 is connected to the second terminal of the absorption resistor 2, the source of the first switching transistor 3, the first terminal of the first capacitor 5, and the cathode of the freewheeling diode 6, respectively, and the second terminal of the third capacitor 12 is connected to the anode of the energy release diode 4, the second terminal of the first capacitor 5, the anode of the freewheeling diode 6, the first terminal of the first resistor 9, and the drain of the second switching transistor 7, respectively. The short-circuit protection diode 11 is used to disconnect the connection with the remaining phase circuits when a short-circuit fault occurs in the phase circuit in which the short-circuit protection diode 11 is located.

[0058] In practical applications, the slave device specifically includes a power supply output module and a short-circuit protection module; the power supply output module and the short-circuit protection module of the slave device are the same as those of the master device.

[0059] The main power phase-shifted parallel circuit design of the four-phase circuit can reduce the current stress of each phase, thereby reducing the heating of the wires caused by the current. It also makes the current ripple of each phase staggered, thus reducing the current ripple and giving the system redundancy. Under the improved master-slave current sharing control algorithm, the master and slave can cooperate in a fault-tolerant manner, improving the robustness of the power supply system.

[0060] In practical applications, it also includes: a voltage and current detection circuit; the voltage and current detection circuit is connected to each phase circuit of the main power phase-shifted parallel circuit, and is used to detect the current and voltage of each phase circuit to obtain analog voltage and current quantities; the analog voltage and current quantities include analog voltage quantities and analog current quantities.

[0061] The purpose of voltage and current detection circuit is to detect the current and voltage of each phase circuit in order to achieve the purpose of state detection and closed loop.

[0062] Taking the LV25-P voltage sensor as an example, this is a closed-loop sensor applying the Hall effect principle. It uses an insulated housing conforming to UL94-V0 standards. For voltage measurement, the ratio of the primary current to the measured voltage must be determined by an external resistor connected in series in the sensor's primary circuit. This sensor boasts numerous advantages, including excellent accuracy, good linearity, low temperature drift, strong anti-interference capability, high common-mode rejection ratio, fast response time, and wide bandwidth. The signal is attenuated by 1 / 15K times by eight resistors before being fed into the LV-25P sampling IC. After being amplified to 2.5 times by the IC's conversion ratio, and then multiplied by 100Ω, the output signal is obtained. After passing through a 1.44x amplifier, a signal suitable for DSP processing is obtained. The voltage sensor circuit is as follows: Figure 2 As shown, this includes 12 resistors (from R6 to R17), amplifier U1B, and two capacitors C11 and C12. The resistance of the eight resistors R7 to R10 and R13 to R16 is 7.5kΩ, the resistance of R6 is 2kΩ, the resistance of R11 is 10kΩ, the resistance of R12 is 1kΩ, the resistance of R17 is 100Ω, and the capacitance of the two capacitors is 0.1μF.

[0063] Taking LEM's HX15-P current sensor as an example, this sensor is also a current sensor developed using the Hall effect principle. It can measure DC, AC, pulse, and various irregular waveforms of current under electrically isolated conditions. It is a voltage output sensor, and the current is converted through the sensor IC with a conversion ratio of 2.67*10e. -5 The current is multiplied by 10kΩ, then amplified by a 1.125V amplifier to a signal suitable for the DSP. The current sensing sensor circuit is as follows: Figure 3 As shown, it includes amplifier U1A, 5 resistors and 4 capacitors. The resistance of resistor R1 is 5.11kΩ, the resistance of resistors R2 to R5 is 10kΩ, the capacitance of the 4 capacitors is 0.1μF, and the IC unit of HX15-P is U2.

[0064] In practical applications, it also includes: a digital signal processor; the digital signal processor is connected to the voltage and current detection circuit, and is used to receive the analog voltage and current quantities and convert the analog voltage and current quantities into digital voltage and current quantities, and output pulses according to the digital voltage and current quantities; the digital voltage and current quantities include digital voltage quantities and digital current quantities.

[0065] The digital signal processor converts analog voltage and current quantities into digital quantities through an on-chip analog-to-digital converter (ADC); it controls the PWM wave output in real time by measuring the current and voltage, so that the output current of the main circuit reaches the set desired value.

[0066] The first switching transistor 3 and the freewheeling diode 6 of the main unit form a buck chopper circuit. The absorption resistor 2 and the capacitor form an RC snubber circuit. The function of the RC snubber circuit is that when the first switching transistor 3 is off, the energy stored in the parasitic inductance charges the parasitic capacitance of the switch, and at the same time, it charges the absorption capacitor 1 through the absorption resistor 2. Due to the effect of the absorption resistor 2, the impedance increases, so the absorption capacitor 1 also effectively increases the parallel capacitance of the switch, thus suppressing the voltage surge when the switch is off. When the switch is on, the absorption capacitor 1 discharges through the switch, and its discharge current is limited by the absorption resistor 2. The second switching transistor 7, together with the digital closed-loop controller, controls the timing of the output current. When the second switching transistor 7 is off, the first switching transistor 3 is also off. The current of the drive coil 13, the freewheeling diode 6, the energy release diode 4, and the filter capacitor together form a freewheeling loop, so that when the current timing is zero, the inductor current can charge the filter capacitor. This allows the coil current to drop rapidly, improving the response speed.

[0067] In terms of selecting switching devices, the traditional approach uses a single IGBT, which has disadvantages such as high switching stress, large voltage overshoot, and low frequency. Using a single MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) has insufficient current capacity and cannot meet the operating requirements. This invention adopts a four-phase parallel mode to overcome the disadvantages of a single IGBT, expand the current margin, and has the function of fault-tolerant operation. Even if one or two circuits fail, the three-phase parallel or two-phase parallel connection can still operate normally.

[0068] The master-slave design provides redundancy to the system. When the master fails, whether it's a short-circuit or open-circuit fault, it will be disconnected from the system, and the next slave will become the master. When a slave experiences an open-circuit fault, since the current expectation and control current timing remain unchanged, the output current of the drive coil 13 will not be disturbed. The slave's short-circuit protection diode 11 automatically disconnects it from the master when a short-circuit fault occurs, while the drive coil 13 can still maintain normal output current, thus ensuring the normal operation of the drive mechanism and increasing the system's reliability.

[0069] In practical applications, the digital signal processor specifically includes a pulse width modulator (PWM); the pulse width modulator is used to adjust the phase of the pulse so that the phase difference between each phase of the main power out-of-phase parallel circuit is 90°.

[0070] Pulse width modulators are used to solve the problem of large current ripple, so that the peaks and troughs of the ripple in a four-phase staggered parallel circuit are staggered, and the phase is modulated as follows: Figure 5 As shown, the four phases are π / 2 out of phase with each other. The horizontal axis represents time and the vertical axis represents displacement. At time 0, the displacements are ordered from smallest to largest as the first phase circuit, the second phase circuit, the fourth phase circuit, and the third phase circuit. V4 represents the first phase circuit, V12 represents the second phase circuit, V20 represents the third phase circuit, and V28 represents the fourth phase circuit.

[0071] This design has the following advantages:

[0072] 1) The circuit has a four-phase staggered parallel circuit. The PWM signal modulated by the circuit has a 90-degree phase difference, which makes the peaks and valleys of the current of each phase intersect and cancel each other out, thereby reducing the current ripple of the drive coil 138.

[0073] 2) The voltage overshoot is small when the switching transistor is turned off, and the high-frequency oscillation phenomenon is not obvious, which enhances the safety, stability and electromagnetic compatibility of the system.

[0074] 3) Reduce the ripple of the coil current and reduce the current stress. Reducing the current stress can reduce losses and heat generation. The current of each phase is only 1 / 4 of that of a traditional rod-controlled power supply. In a traditional rod-controlled power supply, all output power flows through a single switching transistor, which generates a large amount of heat. The multi-phase approach distributes all power losses evenly across all phases, resulting in less thermal stress on each phase component and a more stable system.

[0075] 4) This four-phase staggered parallel circuit features a high redundancy design, enabling fault-tolerant operation and significantly increasing circuit stability and reliability. When a phase fails, whether due to a short circuit, open circuit, or other fault, the main unit will be disconnected from the system, and the next slave unit will become the main unit. The other three phases will allow the system to continue operating stably, with current flowing smoothly. Figure 6 As shown in the figure, the horizontal axis represents time and the vertical axis represents current value. Master_Current represents the master current, Slave_Current1 represents the first slave current, Slave_Current2 represents the second slave current, and Slave_Current3 represents the third slave current.

[0076] The total current is evenly distributed across the three-phase circuit in normal operation. Each phase is reduced from 1 / 4 to 1 / 3 of its original value. The current in drive coil 13 remains in normal current sequence and magnitude, thus ensuring normal operation of the coil and greatly reducing the probability of reactor shutdown caused by hardware failure.

[0077] like Figure 7 As shown, the front stage of the rod-controlled power supply consists of a three-phase rectifier bridge and a large capacitor. The front stage outputs the bus voltage, which serves as the input to the subsequent staggered parallel power circuit. The subsequent stage includes the main topology circuit and the MOSFET drive module. Each phase has a voltage and current monitoring module, which sends the detected voltage and current signals to the DSP for processing, forming a closed-loop control.

[0078] like Figure 8 As shown in the figure, the peaks and troughs of the current ripple in each phase alternate and cancel each other out. After superposition, the total current ripple decreases. The horizontal axis represents time in seconds, and the vertical axis represents current in amperes.

[0079] like Figure 9 As shown, the prototype has a small voltage overshoot and no obvious oscillation phenomenon, which can ensure the safety and stability of the rod control system. The horizontal axis represents time in seconds, and the vertical axis represents voltage in volts.

[0080] In practical applications, it also includes: a drive and protection circuit; the drive and protection circuit is connected to the digital signal processor and the main power phase-shifting parallel circuit respectively, and is used to receive the pulse, drive the first switch 3 and the second switch 7 to close and open, and isolate the main power phase-shifting parallel circuit and the digital signal processor.

[0081] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0082] This invention discloses a modular rod-controlled power supply for nuclear reactors. The main power staggered-phase parallel circuit outputs a timing-controlled current to the drive coil. This circuit is a four-phase circuit, with the first phase acting as the master and the remaining three phases as slaves, connected in parallel. This invention employs a four-phase staggered-phase parallel circuit, controlling each phase circuit with a master-slave current sharing method. Compared to existing technologies using a single IGBT chopper output, this invention's four-phase circuit evenly distributes current stress and voltage, uniformly distributing all power losses across all phases. This results in lower losses on each phase component, reducing the voltage applied to the switching transistors and thus lowering their losses, improving the power supply's electromagnetic compatibility and stability.

[0083] This invention features a highly redundant backup design: when one or two phases of the above four-phase circuit fail, the control circuit can reset the master-slave circuit and re-share the current, ensuring the normal operation of the control rod drive mechanism and greatly reducing the probability of the nuclear reactor shutting down due to rod loss.

[0084] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0085] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A modular rod-controlled power supply for a nuclear reactor, characterized in that, include: The main power phase-shifting parallel circuit is used to output timing control current to the drive coil and drive the drive coil. The main power phase-shifting parallel circuit is a four-phase circuit, with the first phase being the master and the remaining three phases being the slave. The master and the slave are connected in parallel. The host specifically includes: a power output module, a timing control module, and a short-circuit protection module; The power supply output module includes a buck chopper circuit, a resistor-capacitor absorption circuit, a first capacitor, and an energy release diode. The buck chopper circuit includes a first switching transistor and a freewheeling diode. The drain of the first switching transistor is connected to the positive terminal of the input voltage and the cathode of the energy release diode. The source of the first switching transistor is connected to the cathode of the freewheeling diode, the first terminal of the first capacitor, and the short-circuit protection module. The anode of the freewheeling diode is connected to the negative terminal of the input voltage and the timing control module. The cathode of the energy release diode is connected to the positive terminal of the input voltage, and the anode of the energy release diode is connected to the second terminal of the first capacitor, the short-circuit protection module, and the timing control module. When the second switch is turned off, the energy release diode, together with the freewheeling diode and the filter capacitor, forms a freewheeling circuit. The drive coil generates an inductor current and charges the filter capacitor through the freewheeling circuit. The second terminal of the first capacitor is also connected to the short-circuit protection module and the timing control module, respectively; The timing control module includes a second switching transistor, a second capacitor, and a first resistor; The drain of the second switching transistor is connected to the anode of the energy release diode, the second terminal of the first capacitor, and the short-circuit protection module, respectively. The source of the second switching transistor is connected to the negative terminal of the input voltage. The second switching transistor is used to control the timing of the output current and output the current controlling the timing. The short-circuit protection module includes a short-circuit protection diode, a third capacitor, and a first inductor; The anode of the short-circuit protection diode is connected to the second terminal of the first inductor, and the cathode of the short-circuit protection diode is connected to the first terminal of the third capacitor. The first terminal of the first inductor is connected to the second terminal of the absorption resistor, the source of the first switching transistor, the first terminal of the first capacitor, and the cathode of the freewheeling diode. The second terminal of the third capacitor is connected to the anode of the energy release diode, the second terminal of the first capacitor, the anode of the freewheeling diode, the first terminal of the first resistor, and the drain of the second switching transistor. The short-circuit protection diode is used to disconnect the connection with the remaining phase circuits when a short-circuit fault occurs in the phase circuit in which the short-circuit protection diode is located.

2. The modular rod-controlled power supply for a nuclear reactor according to claim 1, characterized in that, Also includes: Three-phase full-wave rectifier and filter capacitor; The three-phase full-wave rectifier is used to perform full-wave rectification on the input voltage, converting the input voltage from alternating current to direct current, and obtaining the rectified input voltage. The filter capacitor is connected to the three-phase full-wave rectifier and the main power phase-shifting parallel circuit, respectively, and is used to filter the rectified input voltage to obtain a rectified and filtered input voltage, which is used as the input voltage of the main power phase-shifting parallel circuit.

3. A modular rod-controlled power supply for a nuclear reactor according to claim 2, characterized in that, The RC snubber circuit includes a snubber resistor and a snubber capacitor. The first terminal of the snubber capacitor is connected to the positive terminal of the input voltage, the cathode of the energy release diode, and the drain of the first switching transistor. The second terminal of the snubber capacitor is connected to the first terminal of the snubber resistor. The second terminal of the snubber resistor is connected to the source of the first switching transistor, the first terminal of the first capacitor, the cathode of the freewheeling diode, and the short-circuit protection module. The RC snubber circuit is used to suppress the voltage surge generated when the first switching transistor is turned off. When the first switching transistor is turned off, the snubber capacitor generates a parasitic inductance and charges the parasitic capacitance of the first switching transistor, and the snubber resistor charges the snubber capacitor. The first terminal of the second capacitor is connected to the second terminal of the first resistor. The second terminal of the second capacitor is connected to the source of the second switching transistor and the negative terminal of the input voltage. The first terminal of the first resistor is connected to the drain of the second switching transistor, the anode of the energy release diode, the second terminal of the first capacitor, the short-circuit protection module, and the anode of the freewheeling diode.

4. A modular rod-controlled power supply for a nuclear reactor according to claim 3, characterized in that, The slave device specifically includes: a power supply output module and a short-circuit protection module; The power supply output module of the slave device is the same as that of the master device; The short-circuit protection module of the slave device is the same as that of the master device.

5. A modular rod-controlled power supply for a nuclear reactor according to claim 1, characterized in that, Also includes: Voltage and current detection circuit; The voltage and current detection circuit is connected to each phase of the main power phase-shifted parallel circuit to detect the current and voltage of each phase circuit and obtain analog voltage and current quantities; the analog voltage and current quantities include analog voltage quantities and analog current quantities.

6. A modular rod-controlled power supply for a nuclear reactor according to claim 5, characterized in that, Also includes: Digital signal processor; The digital signal processor is connected to the voltage and current detection circuit and is used to receive the analog voltage and current quantities and convert them into digital voltage and current quantities, and output pulses according to the digital voltage and current quantities; the digital voltage and current quantities include digital voltage quantities and digital current quantities.

7. A modular rod-controlled power supply for a nuclear reactor according to claim 6, characterized in that, The digital signal processor specifically includes: a pulse width modulator; The pulse width modulator is used to adjust the phase of the pulse so that the phase difference between each phase of the main power out-of-phase parallel circuit is 90°.

8. A modular rod-controlled power supply for a nuclear reactor according to claim 6, characterized in that, Also includes: Drive and protection circuits; The driving and protection circuits are respectively connected to the digital signal processor and the main power phase-shifting parallel circuit, and are used to receive the pulses, drive the first switch and the second switch to close and open, and isolate the main power phase-shifting parallel circuit and the digital signal processor.

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