Auxiliary Heating System Research Articles

Fusion power supply advances by the J-TEXT engineering team

To meet the stringent requirements of the fusion power supply for large-scale fusion devices, the J-TEXT engineering team has carried out key technology research and applications in several important directions of fusion power supply. This article presents the advances made by the J-TEXT engineering team in recent years in the following areas: (1) a high-voltage power supply for an auxiliary heating system; (2) a breakdown protection device for an auxiliary heating power supply; (3) magnetic field compatibility; (4) a high-voltage pulsed power supply for a field-reversed configuration; (5) a large physics experimental facility control system. The research backgrounds, technical progress, test results, applications, summaries and prospects are described in detail in each part. These innovative research results and valuable engineering experience can promote the progress of fusion power supply technology, and also lay a foundation for the development of power supplies with higher parameters in the future.

Recent EAST Experimental Results and Systems Upgrade in Support of Long-Pulse Steady-State Plasma Operation

In recent years, EAST has achieved a 60-s scale steady-state plasma operation (SSO), which is electron dominant heated by the electron cyclotron wave and low hybrid wave. Substantial progresses have been made in the development of long-pulse operation, such as active control of radiative divertor, edge localized mode (ELM) suppression, and He plasma experiment. To further develop the steady-state operation scenario and study the related critical physical issues, the upgrade of EAST has been completed in 2020. The auxiliary heating systems were rearranged and upgraded with a total heating power capability of 33 MW. The 2.45-GHz lower hybrid current drive (LHCD) launcher has been updated from full active multijunction (FAM) to passive active multijunction (PAM) to avoid damage caused by plasma–material interaction. The injection power capability of electron cyclotron resonance heating (ECRH) system is upgraded to 1.4 MW. The upgraded ion cyclotron resonance frequency (ICRF) antenna injects low parallel wavenumber ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$k_{\vert \vert }$ </tex-math></inline-formula> ) spectra with good single pass absorption. The neutral beam injection (NBI) system is moved from F-port to D-port and is reoriented from counterclockwise to clockwise injection. The armor material of lower divertor has been upgraded from graphite to tungsten improving the steady-state heat handling capability from 2 to 10 MW/m2. Based on the upgraded pumping system and improved conductance, the effective pumping speed for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$D_{2}$ </tex-math></inline-formula> of the EAST lower divertor increased twice. With all these upgrades, 100-s scale steady-state operation ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$T_{e0} &gt;10$ </tex-math></inline-formula> keV) and 1056-s high-performance operation with 1.73-GJ injection energy were achieved in 2021 campaigns. The experience in high-performance long-pulse operation obtained on EAST will lay a foundation for the ITER and Chinese Fusion Engineering Testing Reactor (CFETR) operation.

Mechanical effects: challenges for high-field superconducting magnets.

Due to its clean products and sufficient raw materials, fusion energy is expected to become one of the main solutions of the energy crisis and ensuring the sustainable development of human society, which is a long-term strategic frontier field. The promise of fusion energy is to constrain the motion of high-temperature plasma by the high magnetic field generated by superconducting magnets, and then achieve controllable thermonuclear fusion. Fusion power is proportional to the fourth power of the magnetic field strength. Thus, future commercial fusion reactors need a higher magnetic field as the basis for sustainable development [1]. In order to verify the scientific and technological feasibility of fusion energy, China, the United States, the European Union, Russia et al. have jointly participated in the construction of the International Thermonuclear Fusion Test Reactor (ITER), which is expected to produce the first plasma discharge by 2025 [2]. Currently, China is leading the world in many fields of fusion energy research. For example, the experimental advanced superconducting Tokamak (EAST) whole-superconducting Tokamak located at the Institute of Plasma Physics in the Chinese Academy of Sciences has achieved a repeatable world record of stable plasma operation at 120 million degrees Celsius for 101 seconds, which provides a solid foundation for ITER and also China's future Independent Building Fusion Reactor (https://www.cas.cn/syky/202105/t20210528_4790357.shtml). Prof. Jiangang Li, an academician of the Chinese Academy of Engineering, participated in and completed the design and construction of EAST plasma facing componments (PFCs) engineering by the support of the national '9th five-year plan' major scientific and technological infrastructure, and presided over the completion of the national '11th five-year plan' major scientific and technological infrastructure-EAST auxiliary heating system project. He also hosted the national '13th five-year plan' major scientific and technological infrastructure-Integrated Research Facility for Critical Systems of fusion reactor comprehensive research facility for fusion technology (CRAFT). Many important scientific and technological problems have been solved and overcome by Prof. Li and his co-workers, which puts China's plasma physics research and fusion engineering technology at the forefront of global engineering.

Experimental analysis of hybrid dryer combined with spiral solar air heater and auxiliary heating system: Energy, exergy and economic analysis

The simultaneous energy and food resources management can be a challenging problem for researchers working in this field. Solar dryers are equipment that can employ solar energy in order to dry degradable food for long-term storage. However, these systems should also utilize an auxiliary energy source because of non-availability of continuous access to the solar radiation. In this paper, a cabin solar dryer equipped with a heating element as an auxiliary heat source has been used to dry four types of products. The tested products consist of apple, kiwi, banana slices, as well as quince julienne strips. The experiments were performed in four days during autumn, when the solar energy had a low level intensity and the heating element was employed for aiding the energy supply. Temperature and humidity have been measured using temperature and humidity sensors mounted at the inlet and outlet of the collector and dryer cabin. Then the thermal efficiency of the collector and the cabin is investigated via the energy and exergy analysis, and the thermal performance of the system is analyzed. Lastly, an economic analysis is presented to calculate the production cost of per kilogram of products. The results show that thermal efficiency, drying process exergy, produced exergy and specific moisture evaporation rate (SMER) of julienne strips of quince are higher than those of other products. Although banana slices have better conditions in terms of these parameters among the sliced products. Due to the results, it was found that the quince julienne strips have the highest cost about 1.137 $/kg and the lowest drying rate about 0.188 kg/h. On the contrary, the minimum cost belongs to the apple slices about 0.478 $/kg and the maximum drying rate about 0.3224 kg/h.

Economical design optimization of a phase change material active system equipped with a solar collector

Coupling solar air collectors and active systems of phase change materials is an efficient approach for improving building heating supply. Through design optimization, such a system can become economical and energy-efficient in different climates and for different types of buildings. However, previous works have not paid much attention to the economic feasibility of such systems during designing. In this paper, economical design optimization of a system including a solar collector and a PCM heat exchanger was explored. For this purpose, a model that integrated the solar collector, PCM storage, and hut dynamics was developed for the first time. The average mean square error between the measured and predicted hut temperatures over 11 days was 4 °C. The validated model was then used for the design optimization of the system for three different scenarios: office, domestic, and service, with different schedule times and comfort temperatures in the cold season of Auckland. The results showed that the optimum surface area of the solar collector was the same at 1 square metre for all the scenarios; however, the optimum amounts of PCM mass for service, domestic, and office scenarios were 35 kg, 20 kg, and zero, respectively. The optimum values indicate that the system can be cost-effective when used as an auxiliary heating system to meet a portion of the total heating demand.

Enhancing the performance of a greenhouse drying system by using triple-flow solar air collector with nano-enhanced absorber coating

In this research, the impacts of utilizing nano-embedded absorber coating in an auxiliary heater of a greenhouse drying system on the thermal and drying performances have been surveyed empirically. In this context, triple-flow solar air collectors with and without CuO nano-enhanced absorber coating have been designed and manufactured. Designed collectors then integrated to even-span greenhouse dryers to be used as an auxiliary heating device. In the experiments, greenhouse dryers have been tested with and without auxiliary heaters at constant flow rate which is 0.014 kg s−1. According to the experimental findings, utilizing triple-flow solar air heating device with and without nano-embedded paint decreased the drying time as 35.71% and 26.66%, respectively. Thermal and exergetic efficiencies for newly developed collectors were found between the range of 70.39–75.11% and 9.05–10.18%, respectively. In addition, specific energy consumption values were decreased by using collectors with and without nano-enhanced modification from 2.51 to 2.11 and from 2.61 to 2.18 kWh/kg, respectively. Attained outcomes of this study showed the successful utilization of nano-enhanced absorber coating in the auxiliary heating system of the greenhouse dryer.

Analysis and Application of the Equivalent Circuit Model for Core Snubber

Core snubber is a surge suppression protection device installed between the high voltage power supply and the auxiliary heating load. When a breakdown occurs, the core snubber can limit the short-circuit current and consume fault energy, thus protecting the high-voltage power supply and auxiliary heating load. The existing snubber schemes have the problems of large volume, high price, complex integrated design, and large inductance affecting the normal working current of the power supply, so a new expression of equivalent magnetization inductance is established based on the saturated wave theory. The equivalent circuit model of core snubber is improved, and the surge suppression characteristics of core snubber and the attenuation process of breakdown arc current are studied. The circuit model consists of a magnetized inductor and an eddy current resistor in parallel. The expression can be expressed by the characteristic parameters of the alloy winding, the structural size of the core and the voltage integral at both ends of the snubber. In this article, a prototype of iron-based nanocrystalline snubber is made, and a dc high-voltage short-circuit experimental platform is built. By comparing the simulation and measured results of the prototype, the accuracy of the snubber equivalent parallel circuit model derived in this article and its practicability in core design are verified. There are other circuit components in the breakdown discharge circuit of the auxiliary heating system in addition to the distributed capacitance and snubber. In order to further analyze the surge suppression characteristics and breakdown arc current attenuation process of the core snubber including other circuit components, in this article, the extended discharge circuit with reverse bias diode and secondary winding is simulated and tested. The influence of the bridge arm in the reverse bias state on the arc current in the high voltage uncontrolled rectifier during breakdown is discussed. In view of the thickness limitation of core strip, the effectiveness of reasonable setting of secondary winding to avoid core saturation is demonstrated through simulation and measured analysis.

Electron Beam Welding Process of Port Stub of CFETR Vacuum Vessel Sector Mockup

Port structures are important parts of vacuum vessel (VV) in China Fusion Engineer Test Reactor (CFETR), which consists of port stubs and port extensions, mainly provides channels for the installation and maintenance of internal components, such as divertor and blanket, and provides interface for auxiliary heating system, diagnostic system, and vacuum pumping. A 1/8 VV sector mockup with port structures is used to explore the key manufacturing technology of CFETR VV. Electron beam welding (EBW) process development of port structures of 1/8 VV sector mockup is introduced in this article taking the inner shell of upper port stub as an example. Through EBW test and process optimization, the surface formation, microstructure, and mechanical properties of the weld are obtained. On this basis, the EBW of the inner shell of the upper port stub is carried out. After phased array ultrasonic nondestructive testing and laser tracker measurement, the weld quality is excellent, and contour accuracy has reached the technical requirements. This study provides important support for the engineering design and construction of the CFETR.

Design of the Water-Cooled Ceramic Breeder blanket for CFETR

The Water-Cooled Ceramic Breeder (WCCB) blanket is one of the blanket candidates for the Chinese Fusion Engineering Testing Reactor (CFETR). In the current version, the WCCB blanket was designed to fulfill the requirements of operating in multiple fusion power modes (200 MW, 500 MW, 1 GW and 1.5 GW) of CFETR while satisfying the tritium self-sufficiency. Structural designs were carried out for typical inboard and outboard modules. Adequate neutron shielding capability and acceptable thermo-mechanical performance were achieved according to the analyses. The global Tritium Breeding Ratio (TBR) was 1.165 with full blanket coverage. It reduced to 1.052 considering the ports occupied by auxiliary heating systems and diagnostic systems. Eventually, the TBR increased to 1.123 by applying the approach of divertor blanket. Besides, two independent cooling systems were applied to adapt to different fusion powers. One cooling system provided coolant for the first wall, the other for breeder zones. The corresponding Primary Heat Transfer System (PHTS) was designed and main operation parameters were obtained under the fusion power of 200 MW∼1.5 GW.

Rapid die preheating using a high-power infrared lamp array

• Preheating HPDC dies for automotive transmission components was investigated. • Radiation heat transfer into HDPC dies was simulated using the Monte Carlo method. • Heater configuration was optimized to increase heat rate while minimizing hot spots. • Radiation shield was effective in minimizing hot spots on protruding surfaces. High pressure die casting (HPDC) is a highly violent process that causes significant wear on the die from chemical attacks and from repeated cycling at high pressure and temperature. In practice, HPDC dies are usually preheated by injecting aluminum into the die as warm-up shots. Although warm-up shots transfer heat into the die at a high rate, the warm-up shots are often rejected as scrap due to defects caused by the lower-than-optimal die temperature. The present work aims to develop an auxiliary heating system using an array of high-power, electric infrared lamps to preheat an HPDC die. The potential advantage of this method is a reduction in scrap material and a reduction in thermal cycles on the casting die. Experiments were conducted to quantify the heating rate for various infrared electric heater configurations. A numerical model was also developed to simulate the radiation heat transfer from the lamp array to the die. The model was validated against experiments and subsequently used to optimize the configuration of the heater. The heating system was improved by adding a small radiation shield to minimize hot spots on protruding surfaces while still maintaining a fast heating time. The validated numerical model can be used in the future to develop custom heater solutions for different die geometries.

발열유리 창호시스템의 발열량에 따른 실내공간 열적 쾌적성능 분석

Purpose: In this study, an approach using the heated glazing window system as an auxiliary heating system is evaluated in terms of thermal comfort. Heat loss through window parts can occur relatively high because of low thermal resistance, which causes keeping lower surface temperature of the window, typically when outdoor air temperature is lower. With such issues, occupants may feel thermal discomfort near window parts mainly due to the radiant temperature asymmetry. In this study, an approach using the heated glazing window system as an auxiliary heating system is proposed to improve the performance of occupant‘s thermal comfort in a conditioned room. Method: For this analysis, a floor radiant heating system is considered as the main heat supply system in the conditioned zone. The internal thermal information of the room is calculated using a two-dimensional heat transfer analysis simulation (i.e., TRISCO). To quantitatively analyize the thermal comfort of the space adjacent to the window, the Predicted Mean Vote(PMV) at each point is derived by dividing the internal space into a two-dimensional grid. Result: As a result of the analysis, it was found that the heated glazing window system contributes to making the indoor thermal comfort uniform and can improve the thermal comfort of the window adjacent area. The maximum PPD deviation of the indoor space is about 6.3% when the heated glazing system is not operated, 1.8% under the heating of 20W/㎡, and 0.08% under the heating of 40W/㎡

Mass flow rate optimization in solar heating systems based on a flat-plate solar collector: A case study

Little works considered the optimization of working fluids in solar systems. Engineers, designers and scientists are interested with the optimization problems, furthermore it is very important specially, for solar systems to improve the energetic behavior and increase their efficiencies as a conversion system of solar irradiance to a useful thermal power. According to the available literature, the criteria of optimization mainly relates to energetic and economic analysis (one of them or both). The analysis was based upon the maximum useful energy obtained from solar collector. Accordingly, the optimum mass flow rate was found aspires to infinity. The second analysis is based upon minimum cost of the unit of useful energy [$/W]. The optimum mass flow rate of solar air-heating flat-plate collector for the considered domestic solar heating system has been found 29 kg/h per square meters of solar collectors. This paper deals with a third criteria that is, the amount of the additional energy required to achieve the required task from the solar system by means of auxiliary heating system. In where both the outlet temperature and mass flow rate play crucial role in the heat exchange between the fluid in the collector loop and the fluid in the load loop.

Containment structures and port configurations

This article describes the DEMO cryostat, the vacuum vessel, and the tokamak building as well as the system configurations to integrate the main in-vessel components and auxiliary systems developed during the Pre-Conceptual Design Phase.The vacuum vessel is the primary component for radiation shielding and containment of tritium and other radioactive material. Various systems required to operate the plasma are integrated in its ports. The vessel together with the external magnetic coils is located inside the even larger cryostat that has the primary function to provide a vacuum to enable the operation of the superconducting coils in cryogenic condition. The cryostat is surrounded by a thick concrete structure: the bioshield. It protects the external areas from neutron and gamma radiation emitted from the tokamak. The tokamak building layout is aligned with the VV ports implementing floors and separate rooms, so-called port cells, that can be sealed to provide a secondary confinement when a port is opened during in-vessel maintenance.The ports of the torus-shaped VV have to allow for the replacement of in-vessel components but also incorporate plasma limiters and auxiliary heating and diagnostic systems. The divertor is replaced through horizontal ports at the lower level, the breeding blanket (BB) through upper vertical ports. The pipe work of these in-vessel components is also routed through these ports. To facilitate the vertical replacement of the BB, it is divided into large vertical segments. Their mechanical support during operation relies on vertically clamping them inside the vacuum vessel by a combination of obstructed thermal expansion and radial pre-compression due to the ferromagnetic force acting on the breeding blanket structural material in the toroidal magnetic field.

Increasing the energy efficiency of a building by thermal insulation to reduce the thermal load of the micro-combined cooling, heating and power system

The paper analyzes the energy consumption of an energy-independent house in two different situations, namely when the exterior insulation is installed and, respectively, in its absence. The result of the analysis was used to assess the reduction of fuel consumption and greenhouse gas emissions of the auxiliary heating system, namely a biomass boiler. The home’s heating system consists of a Stirling cogeneration system with biogas, which produces 3 kW of electricity and 9 kW of heat, and a 50 kW biomass boiler. The biomass boiler must provide the additional heat necessary to cover the consumption of the house when the Stirling engine is running and respectively ensure the coverage of the complete heat consumption of the building when the Stirling engine is in standby mode. The analysis showed that the installation of external insulation on the building walls will reduce energy consumption by 13%–16%, depending on the variation of the outside air temperature.

Neutronics assessments of LHCD antenna system for CFETR

To maintain a long-duration plasma current and obtain steady-state operation for CFETR, a non-inductive Heating and Current Drive (H&CD) system is currently under study. Lower Hybrid Current Drive (LHCD) is an important auxiliary heating system, that has good current drive efficiency and improves plasma confinement by changing the current distribution.Neutronics calculation was conducted to study the nuclear performance and shielding effectiveness. This study was performed on a CFETR 22.5° model integrated with an upper-port LHCD antenna structure. The detailed 3D neutronics model was built using the computer-aided modeling platform cosVMPT, and particle transport was performed using MCNP5 with the nuclear data library FENDL-2.1. With the support of high performance variance reduction technique, “on-the-fly” GVR method, global neutron and photon flux distributions with reasonable relative error were obtained. The irradiation damage to components in the antenna system was assessed, including DPA, gas production and nuclear heat density. The total nuclear heat for the transmission structure was 1.192 MW, and the peak irradiation damage was located at the front end of the Passive-Active Multi-junction (PAM) launcher. Owing to the blanket opening for wave propagation, the induced nuclear responses for VV and TFC were analyzed, and the shielding design was initialized. The results showed that all the parameters were within the design limit after the shielding design. Because part of the blanket module was occupied by the antenna launcher, the TBR of CFETR was evaluated, and it decreased by only 0.22% for the whole fusion reactor.

Neutron characterization analysis of the negative ion-based neutral beam verification facility for CFETR

Neutral beam injection heating with negative ion source is one of the important auxiliary heating system to achieve the high parameter steady- state operation goal for CFETR. A Negative ion-based Neutral Beam Verification Facility (NNBVF), a conceptual design for testing the engineering feasibility of neutral beam injection systems, is proposed for the Chinese Fusion Engineering Test Reactor (CFETR). The neutral-beam injectors used for CFETR will operate with deuterium. Inevitably, a large number of neutrons are generated between beam deuterons and deuterons implanted in the calorimeter. Neutron source is one of the important input data for radiation analysis. The neutron characterization on the calorimeter surface were explored by using a multiaperture Gaussian divergence model and the local mixing model. The total neutron intensity reach up to 1.2 × 1014 n/s for 400 keV deuteron beam. Initial results revealed that the aspect ratio of the neutron beam profile decreases with increasing beam divergence. The shape of the neutron profile on the calorimeter surface remains the same for the beam density distributions. This implies the neutron intensity emitted from the target is suitable for the beam density distribution diagnostic applications.

Diseño de un captador solar híbrido con captador solar de placa plana y calentamiento por inducción: evaluación y modelado con regresión de componentes principales

Food drying is one of the main food preservation processes, which are supplied with electrical energy (EE). Recently, the EE has had constant increases in its costs, prompting the integration of renewable energy sources for these processes. Therefore, the objective of this research was to design, build and model a hybrid solar collector (HSC-IH) for drying food, made up of solar energy (SE) through a solar collector and EE by means of induction heating. (IH), this work prioritizes the incorporation of an auxiliary heating system for the solar collectors, minimizing temperature variability and increasing its heat capacity, the HSC-IH has a collection surface of 1 m2, adjustable flow of 0.3 - 4 CMM and maxim of 80 ° C, the prediction model developed with PCR, to determine the outlet temperature (OT) provided by the HSC-IH with only the use of solar energy and to estimate the energy provided by the EE with the IH, the final model it has an R2 of 0.934 and can be used to understand the OT of HSC-IH.

Concentrating photovoltaic/thermal collectors coupled with an anaerobic digestion process: Dynamic simulation and energy and economic analysis

This work presents a dynamic analysis of an anaerobic digestion plant, in which concentrating photovoltaic/thermal collectors are used to match a part of both heating and power demand of the process. The system is supplied by the organic fraction of municipal solid waste. The system also includes a thermal storage tank and an auxiliary heating system. An up-grade section is also included, to produce biomethane, suitable for injection into the natural gas pipeline network.For such hybrid solar-biomass system, a comprehensive simulation model was developed in MATLAB®, calculating the time-dependent production of biomethane as a function of the operating temperature within the digester. The model, based on differential equations and thermal balances, accounts for both thermal and biological phenomena occurring within the process, taking into consideration the geometrical and structural characteristics of the system. The consistent Anaerobic Digestion Model 1 is used to model the biological process, evaluating the biogas production as a function of a series of operating variables: the digester operating temperature, mass flowrate and temperature of the hot water entering the digester, ambient temperature, mass flowrate and composition of the organic waste in input. The model also calculates the electric consumption of the upgrading process, used to convert the biogas into biomethane. Such model was integrated into the simulation platform of the overall plant, developed in TRNSYS, evaluating the energy, environmental and economic performance of the entire system. A case study is presented, showing the dynamic performance of the system under evaluation: for such case, a primary energy saving of 24% was found, with respect to a conventional digester; around 20% of the overall thermal energy demand is met by solar energy; finally, a promising payback time of about 3 years was estimated.

Design and optimization of an advanced time-of-flight neutron spectrometer for deuterium plasmas of the large helical device.

A time-of-flight neutron spectrometer based on the Time-Of-Flight Enhanced Diagnostic (TOFED) concept has been designed and is under development for the Large Helical Device (LHD). It will be the first advanced neutron spectrometer to measure the 2.45MeV D-D neutrons (DDNs) from helical/stellarator plasmas. The main mission of the new TOFED is to study the supra-thermal deuterons generated from the auxiliary heating systems in helical plasmas by measuring the time-of-flight spectra of DDN. It will also measure the triton burnup neutrons (TBNs) from the d+t reactions, unlike the original TOFED in the EAST tokamak. Its capability of diagnosing the TBN ratios is evaluated in this work. This new TOFED is expected to be installed in the basement under the LHD hall and shares the collimator with one channel of the vertical neutron camera to define its line of sight. The distance from its primary scintillators to the equatorial plane of LHD plasmas is about 15.5m. Based on Monte Carlo simulation by a GEANT4 model, the resolution of the DDN energy spectra is 6.6%. When projected onto the neutron rates that are typically obtained in LHD deuterium plasmas (an order of 1015 n/s with neutral beam injection), we expect to obtain the DDN and TBN counting rates of about 2.5 · 105 counts/s and 250 counts/s, respectively. This will allow us to analyze the DDN time-of-flight spectra on time scales of 0.1s and diagnose the TBN emission rates in several seconds with one instrument, for the first time in helical/stellarator plasmas.

Upgrade of the cathode HVPS system for 4.6 GHz LHCD on EAST using high speed PSM

The 4.6GHz LHCD system is an important part of the auxiliary heating system on EAST tokamak. The cathode high voltage power supply(HVPS) is based on pulse step modulation (PSM) technology, in which 64 modules are used to output 50kVDC in series. The modulation frequency of single PSM module is 50Hz, it switch on and off every 20ms, so the regulation speed of system is limited. In the face of the interference caused by the voltage fluctuation of the grid side during the tokamak operation, the HVPS cannot make more rapid response. It means that a large fluctuation of the output voltage will be produced and output performance of microwave will be affected. In order to improve the regulation speed and anti-interference capability of system, the high frequency PSM module with 1kHz modulation frequency capability was designed to replace some of the original low frequency modules. The fluctuation of output voltage was reduced by the rapid regulation capability of the high frequency module. The experimental results show that the output voltage fluctuation rate of the upgraded power supply is reduced by 50%, which better meets the control requirements of klystron for voltage accuracy and stability, and the reliability of the system is guaranteed.