Temperature rise simulation test device and test method for saturable reactor under pulse voltage

Abstract

The invention discloses a temperature rise simulation test device and method for a saturable reactor under pulse voltage. The temperature rise simulation test device for the saturable reactor under pulse voltage comprises a continuous pulse voltage generation module, a cooling water module and a measurement module. The continuous pulse voltage generation module comprises an AC power supply, a rectification silicon stack, an energy storage capacitor, a continuous pulse generator and a switching frequency regulator. The measuring module comprises an optical fiber temperature sensor arranged on the surface of the saturable reactor. And the temperature of the saturable reactor at different time degrees is measured through the optical fiber temperature sensor so as to measure the temperature rise of the saturable reactor during testing. The test device is formulated according to the heating characteristics of the saturable reactor, the heating of the iron core of the saturable reactor caused by the turn-on and turn-off processes of the thyristor in reality is truly reproduced, and the accuracy of the temperature rise test result of the saturable reactor is improved. The invention further provides a test method.

Description

Technical Field

[0001] The invention relates to the technical field of reactors, and in particular to a temperature rise simulation test device and a test method for a saturated reactor under a pulse voltage. Background Art

[0002] China's energy is unevenly distributed due to geographical factors. For example, hydropower is mainly concentrated in the southwest of my country, while thermal power, solar energy and wind energy are mainly concentrated in North China and Northwest my country, resulting in a distance of 1,000 to 3,000 km between the power generation end and the power receiving end. DC transmission is the best choice for long-distance power transmission. Therefore, my country has built a power transmission network with the largest number of DC projects, the largest transmission capacity and the longest lines in the world. The use of a large number of DC power grids and a wide range has put forward higher requirements for the reliability indicators of DC systems. The converter valve is the core device of the DC transmission project. It is a functional component that converts AC power into DC power. The saturated reactor is a key component used to provide protection in the converter valve. Therefore, the reliability of the saturated reactor will directly affect the normal operation of the converter valve. Since the saturated reactor is a current-type component, it will generate a lot of heat during operation, which will cause its temperature to rise. When the high temperature rises to a certain level, the saturated reactor will be damaged.

[0003] As we all know, the saturated reactor is a core-type reactor, which is mainly composed of a coil, an iron core, a potting material, a shell, etc. The coil is made of metal and insulating materials. During the manufacturing process, the insulation between the turns and the insulation between the coil and the iron core are formed. The metal conductor of the coil is a spiral-shaped hollow aluminum tube. The temperature rise of the saturated reactor is mainly determined by the iron core. The iron core itself is a combination of heat generation and heat dissipation. The heat generation comes from the pulse voltage that occurs when the converter valve is turned on or off, which causes hysteresis loss, eddy current loss, abnormal loss, etc. inside the iron core. These losses will cause the temperature of the iron core to rise. The cooling of the iron core depends on the heat dissipation medium, that is, the cooling water inside the coil and the air heat dissipation of the shell. The loss of the saturated reactor is caused by the heat generated by the DC resistance of the coil. This loss plus the iron loss generated by the heating of the iron core will constitute a heating power of several kilowatts. Therefore, if there is no cooling medium to take away the heat, the saturated reactor will reach the upper temperature limit in a short time. Therefore, the heat dissipation effect of the saturated reactor determines whether the reactor can function normally.

[0004] The existing heat dissipation method is to pass cooling water through the hollow aluminum tube of the coil, so that its flow rate reaches tens of liters per minute, so that the several kilowatts of heat generated in the coil are taken out of the coil by the cooling water. However, whether this existing method is effective or not, an effective method is needed to conduct tests, by simulating the temperature rise of the saturated reactor under actual operating conditions, so as to provide a basis for the design of the saturated reactor. Summary of the invention

[0005] In view of this, the present invention provides a temperature rise simulation test device and test method for a saturated inductor under a pulse voltage to meet the above requirements.

[0006] A temperature rise simulation test device for a saturated reactor under a pulse voltage, wherein the saturated reactor comprises an iron core and a coil arranged on the iron core, wherein the coil is a hollow tube. The temperature rise simulation test device for a saturated reactor under a pulse voltage comprises a continuous pulse voltage generation module for supplying the saturated reactor, a cooling water module for maintaining the working temperature of the saturated reactor, and a measurement module for measuring the working parameters of the saturated reactor. The continuous pulse voltage generation module comprises an AC power supply, a rectifier silicon stack electrically connected to the AC power supply, an energy storage capacitor connected in parallel and electrically connected to the AC power supply and the rectifier silicon stack, a continuous pulse generator electrically connected to one end of the energy storage capacitor, and a switching frequency regulator for controlling the working state of the continuous pulse generator. The rectifier silicon stack is used to adjust AC power to DC power. The energy storage capacitor is used to discharge when the rectifier silicon stack is reversely powered, and to charge when the rectifier silicon stack is forwardly powered. The continuous pulse generator is used to generate a rectangular pulse electrical test signal. The switching frequency regulator is used to adjust the frequency of the signal in the circuit. The cooling water module delivers deionized water heated to 50°C to the coil of the saturated reactor for circulation temperature control. The measuring module includes an optical fiber temperature sensor disposed on the surface of the saturated reactor. The optical fiber temperature sensor is used to measure the temperature of the saturated reactor at different times to measure the temperature rise of the saturated reactor during testing.

[0007] Furthermore, the saturable reactor is connected in parallel with the continuous pulse generator and the AC power supply.

[0008] Furthermore, the measurement module also includes a current sensor electrically connected to the saturated inductor, and a voltage sensor electrically connected to the saturated inductor, the voltage sensor and the current sensor are electrically connected to a digital oscilloscope, and the digital oscilloscope displays the pulse voltage waveform of the saturated inductor to ground and the pulse current waveform flowing through the inductor coil.

[0009] Furthermore, the voltage waveform and the current waveform are used to calculate core loss.

[0010] Furthermore, the method for calculating the core loss is to multiply the measured voltage waveform and current waveform and then integrate the time.

[0011] The test method of the temperature rise simulation test device of the saturated reactor under the pulse voltage comprises the following steps:

[0012] STEP 101: Electrically connect the saturated reactor, the continuous pulse voltage generating module, the cooling water module, and the measuring module;

[0013] STEP102: Provide deionized water and adjust the water flow, cooling water temperature and conductivity of the cooling water system according to the temperature rise test requirements;

[0014] STEP103: Start the continuous pulse voltage generating module to establish a stable discharge voltage at both ends of the saturated reactor, and when the peak value of the discharge voltage reaches the actual operating condition of the converter valve, adjust the switching frequency regulator so that the frequency of the pulse voltage loaded on the saturated reactor reaches 50 Hz; STEP104: Measure the voltage and current waveforms of the saturated reactor 1 through the measuring module to calculate the core loss;

[0015] STEP 105: Maintain the amplitude and frequency of the discharge voltage, monitor the temperature of the saturated reactor through a temperature sensor when the temperature of the saturated reactor reaches a thermal equilibrium state, and evaluate the thermal design of the saturated reactor and the thermal tolerance of the insulating material based on the measured temperature of the saturated reactor; STEP 106: Record the relationship between the temperature rise and the core loss when the saturated reactor reaches the thermal equilibrium state.

[0016] Furthermore, the flow rate of the cooling water system is 30 L / min, the cooling water temperature is 60° C., and the conductivity is 0.5-1 μS / cm.

[0017] Furthermore, in STEP 103, the discharge voltage is set to excite the saturated reactor core to a deep saturation state.

[0018] Compared with the prior art, the temperature rise simulation test device of the saturated reactor under pulse voltage provided by the present invention is formulated around the heating characteristics of the saturated reactor, that is, firstly, through the temperature equivalence method, a constant cooling water temperature is used to replace the temperature generated by the coil of the saturated reactor due to heating under the actual pulse working condition of the converter valve, and secondly, the pulse voltage borne by the saturated reactor under the actual operating condition is simulated, that is, the actual iron core is stimulated to a deep saturation state caused by the thyristor opening and closing process is simulated by the switching frequency regulator, which truly reproduces the heating of the saturated reactor iron core caused by the opening and closing process of the thyristor in reality, and improves the accuracy of the temperature rise test results of the saturated reactor. In addition, the temperature rise simulation test device simplifies the complexity of the test device and optimizes the floor space of the test device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1The present invention provides a principle block diagram of a temperature rise simulation test device for a saturated reactor under a pulse voltage. DETAILED DESCRIPTION

[0020] The specific embodiments of the present invention are further described in detail below. It should be understood that the description of the embodiments of the present invention herein is not intended to limit the protection scope of the present invention.

[0021] like Figure 1 As shown, it is a principle block diagram of the temperature rise simulation test device of the saturated reactor under pulse voltage provided by the present invention. The temperature rise simulation test device of the saturated reactor under pulse voltage is used to simulate the test of a saturated reactor 100 for a converter valve. The saturated reactor 100 for a converter valve is a prior art, which includes an iron core and a coil wound on the iron core. The coil is made of a hollow aluminum tube. The temperature rise simulation test device of the saturated reactor under pulse voltage includes a continuous pulse voltage generating module 10 for supplying the saturated reactor, a cooling water module 20 for maintaining the working temperature of the saturated reactor, and a measuring module 30 for measuring the working parameters of the saturated reactor. It can be imagined that the temperature rise simulation test device of the saturated reactor for the converter valve under pulse voltage conditions also includes some other functional modules, such as electrical connection components, switching devices, etc., which are well known to those skilled in the art and will not be repeated here.

[0022] The continuous pulse voltage generating module 10 includes an AC power supply 11, a rectifier silicon stack 12 electrically connected to the AC power supply 11, an energy storage capacitor 13 electrically connected in parallel to the AC power supply 11 and the rectifier silicon stack 12, a continuous pulse generator 14 electrically connected to one end of the energy storage capacitor 13, and a switching frequency regulator 15 for controlling the working state of the continuous pulse generator 14. The AC power supply 11 can be a commercial power supply, which is a prior art and will not be described in detail here. The rectifier silicon stack 12 itself is a prior art, which is composed of a plurality of silicon high-frequency diodes connected in series, and is packaged with high-frequency ceramics on the outside, and the working voltage is between several thousand volts and tens of thousands of volts. The rectifier silicon stack 12 is used to adjust the AC power to DC power, and is connected in series with the AC power supply 11. The energy storage capacitor 13 itself is also a prior art, which is used to discharge when the rectifier silicon stack 12 is reversely powered, and to charge when the rectifier silicon stack 12 is forwardly powered, so as to provide a continuous DC voltage for the entire circuit. Therefore, the two ends of the energy storage capacitor 13 are electrically connected to one end of the rectifier silicon stack 12 and the other end of the AC power supply 11, that is, the energy storage capacitor 13 is connected in parallel with the rectifier silicon stack 12 and the AC power supply 11. The continuous pulse generator 14 itself is also a prior art, which can generate rectangular pulses with adjustable width, amplitude and repetition frequency, thereby generating an electrical test signal of the required parameters. In this embodiment, the continuous pulse generator 14 can generate a pulse voltage required by the specification. The switching frequency regulator 15 is also called a discharge frequency regulator, which is also a prior art. Its main function is to adjust the frequency of the signal in the circuit to adapt it to different application scenarios. The frequency regulator usually includes an oscillator, a mixer and a filter. The desired output signal is obtained by mixing the frequency signal to be adjusted with a reference signal and removing the undesired frequency components through a filter. The saturated inductor 100 is electrically connected to the output end of the continuous pulse generator 14 and one end of the energy storage capacitor 13, so that a continuous pulse voltage can be applied to the saturated inductor 100.

[0023] The cooling water module 20 includes a circulating water pump, a water reservoir, and a plurality of water pipes. The circulating water pump transmits deionized water heated to 50°C to the coil of the saturated reactor 100 for circulation and temperature control. The water pipes are respectively connected to the input end and the output end of the coil and are connected to the circulating water pump. The water reservoir is used to store the deionized water. The reason for using the deionized water is that deionized water has excellent electrical insulation and heat dissipation properties, which is crucial for the high-voltage and high-power working environment of the converter valve. In addition, the use of deionized water can reduce the electrochemical corrosion of metals in the system loop and can increase the service life of the equipment. The main reason for heating the deionized water to 50 degrees Celsius is to simulate the temperature during the actual operation of the converter valve. Therefore, during the actual operation, the inlet temperature of the water supplied to the saturated reactor is about 50 degrees Celsius. If it is not heated to 50 degrees Celsius, the thermal stress of the saturated reactor during the actual operation cannot be correctly simulated.

[0024] The measuring module 30 includes an optical fiber temperature sensor 31 disposed on the surface of the saturated reactor 100, a current sensor 32 electrically connected to the saturated reactor 100, and a voltage sensor 33 electrically connected to the saturated reactor 100. The temperature of the saturated reactor 100 at different times is measured by the optical fiber temperature sensor 31. The voltage sensor 33 and the current sensor 32 are electrically connected to a digital oscilloscope, and the pulse voltage waveform of the saturated reactor 100 to the ground and the pulse current waveform flowing through the reactor coil are displayed by the digital oscilloscope.

[0025] The present invention also provides a temperature rise simulation test method for a saturated reactor under a pulse voltage, which comprises the following steps:

[0026] STEP 101: electrically connect the saturated reactor 100, the continuous pulse voltage generating module 10, the cooling water module 20, and the measuring module 30;

[0027] STEP102: Provide deionized water and adjust the water flow, cooling water temperature and conductivity of the cooling water system according to the temperature rise test requirements;

[0028] STEP 103: Start the continuous pulse voltage generating module 10 to establish a stable discharge voltage at both ends of the saturated reactor 100, and when the peak value of the discharge voltage reaches the actual operating condition of the converter valve, adjust the switching frequency regulator 15 so that the frequency of the pulse voltage loaded on the saturated reactor 100 reaches 50 Hz;

[0029] STEP 104: Measure the voltage and current waveforms of the saturable reactor 100 through the measurement module 30 to calculate the core loss;

[0030] STEP 105: maintaining the amplitude and frequency of the discharge voltage, monitoring the temperature of the saturated reactor 100 through a temperature sensor when the temperature of the saturated reactor 100 reaches a thermal equilibrium state, and evaluating the thermal design of the saturated reactor 100 and the thermal tolerance of the insulation material according to the measured temperature of the saturated reactor 100;

[0031] STEP 106: Record the relationship between the temperature rise and the core loss of the saturated reactor 100 when it reaches the thermal equilibrium state.

[0032] In step STEP102, the water flow rate is designed to meet the heat dissipation of the saturated reactor 100 so that it can drop to the rated temperature. The actual operating condition of the saturated reactor 100 is simulated by adjusting the temperature of the cooling water, that is, the temperature of the converter valve during actual operation is simulated, because the inlet water temperature of the saturated reactor 100 is about 50 degrees Celsius in actual operation. In this embodiment, the test requirements are that the flow rate of the cooling water system is 30L / min, the cooling water temperature is 50℃, and the conductivity is 0.5-1μS / cm.

[0033] In step STEP104, the method for calculating the core loss is to multiply the voltage waveform and the current waveform measured by the measuring module 30, and then integrate the time. The calculation program can be executed on a computer and will not be described in detail here.

[0034] In STEP 105, the thermal equilibrium state means that when the time change rate of the reactor detection temperature is less than 1K / h, that is, 1°C / hour, and is maintained for 3 to 4 hours, it can be determined that the saturated reactor has reached a thermal equilibrium state. The thermal tolerance of the insulating material means that the saturated reactor temperature that can be reached meets the heat resistance grade of the insulating material used. In addition, the setting of the discharge voltage should excite the core of the saturated reactor 100 to a deep saturation state, thereby simulating the heating condition of the saturated reactor during normal operation.

[0035] In STEP 106, based on the measured temperature rise, core loss, and the relationship between the temperature rise and the core loss, it is judged whether the saturated reactor meets the standard according to the standard, and a basis is also provided for the design of the saturated reactor 100.

[0036] Compared with the prior art, the temperature rise simulation test device of the saturated reactor under pulse voltage provided by the present invention is formulated around the heating characteristics of the saturated reactor, that is, firstly, through the temperature equivalence method, a constant cooling water temperature is used to replace the temperature generated by the coil of the saturated reactor 100 due to heating under the actual pulse working condition of the converter valve, and secondly, the pulse voltage borne by the saturated reactor under the actual operating condition is simulated, that is, the actual thyristor opening and closing process is simulated by the switching frequency regulator 15 to cause the iron core to be excited to a deep saturation state, which truly reproduces the heating of the saturated reactor iron core caused by the opening and closing process of the thyristor in reality, and improves the accuracy of the temperature rise test results of the saturated reactor 100. In addition, the temperature rise simulation test device simplifies the complexity of the test device and optimizes the floor space of the test device.

[0037] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modification, equivalent substitution or improvement within the spirit of the present invention is included in the scope of the claims of the present invention.

Claims

1. A temperature rise simulation test device for a saturated reactor under a pulse voltage, wherein the saturated reactor comprises an iron core and a coil arranged on the iron core, wherein the coil is a hollow tube, and wherein: The temperature rise simulation test device of the saturated inductor under pulse voltage includes a continuous pulse voltage generating module for supplying the saturated inductor, a cooling water module for maintaining the working temperature of the saturated inductor, and a measuring module for measuring the working parameters of the saturated inductor. The continuous pulse voltage generating module includes an AC power supply, a rectifier silicon stack electrically connected to the AC power supply, an energy storage capacitor connected in parallel and electrically connected to the AC power supply and the rectifier silicon stack, a continuous pulse generator electrically connected to one end of the energy storage capacitor, and a switching frequency regulator for controlling the working state of the continuous pulse generator. The rectifier The silicon stack is used to adjust alternating current into direct current, the energy storage capacitor is used to discharge when the rectifier silicon stack is powered on in the reverse direction, and to charge when the rectifier silicon stack is powered on in the forward direction, the continuous pulse generator is used to generate a rectangular pulse electrical test signal, the switching frequency regulator is used to adjust the frequency of the signal in the circuit, the cooling water module transmits deionized water heated to 50°C to the coil of the saturated inductor for circulating temperature control, and the measuring module includes an optical fiber temperature sensor arranged on the surface of the saturated inductor, and the optical fiber temperature sensor is used to measure the temperature of the saturated inductor at different times to measure the temperature rise of the saturated inductor during testing.

2. The temperature rise simulation test device of a saturated reactor under a pulse voltage as claimed in claim 1, characterized in that: The saturable reactor is connected in parallel with the continuous pulse generator and the AC power supply.

3. The temperature rise simulation test device of a saturated reactor under a pulse voltage as claimed in claim 1, characterized in that: The measurement module also includes a current sensor electrically connected to the saturated inductor, and a voltage sensor electrically connected to the saturated inductor. The voltage sensor and the current sensor are electrically connected to a digital oscilloscope, and the pulse voltage waveform of the saturated inductor to ground and the pulse current waveform flowing through the inductor coil are displayed through the digital oscilloscope.

4. The temperature rise simulation test device of a saturated reactor under a pulse voltage as claimed in claim 3, characterized in that: The voltage waveform and the current waveform are used to calculate the core loss.

5. The temperature rise simulation test device of a saturated reactor under a pulse voltage as claimed in claim 3, characterized in that: The core loss is calculated by multiplying the measured voltage and current waveforms and then integrating them with respect to time.

6. A test method for a temperature rise simulation test device for a saturated reactor under a pulse voltage according to any one of claims 1 to 5, comprising the following steps: STEP 101: Electrically connect the saturated reactor, the continuous pulse voltage generating module, the cooling water module, and the measuring module; STEP102: Provide deionized water and adjust the water flow, cooling water temperature and conductivity of the cooling water system according to the temperature rise test requirements; STEP103: Start the continuous pulse voltage generating module to establish a stable discharge voltage at both ends of the saturated reactor, and when the peak value of the discharge voltage reaches the actual operating condition of the converter valve, adjust the switching frequency regulator so that the frequency of the pulse voltage loaded on the saturated reactor reaches 50 Hz; STEP104: Measure the voltage and current waveforms of the saturated reactor 1 through the measuring module to calculate the core loss; STEP 105: Maintain the amplitude and frequency of the discharge voltage, monitor the temperature of the saturated reactor through a temperature sensor when the temperature of the saturated reactor reaches a thermal equilibrium state, and evaluate the thermal design of the saturated reactor and the thermal tolerance of the insulating material based on the measured temperature of the saturated reactor; STEP 106: Record the relationship between the temperature rise and the core loss when the saturated reactor reaches the thermal equilibrium state.

7. The test method according to claim 6, characterized in that: The flow rate of the cooling water system is 30 L / min, the cooling water temperature is 60° C., and the conductivity is 0.5-1 μS / cm.

8. The test method according to claim 7, characterized in that: In STEP 103, the discharge voltage is set to excite the saturable reactor core to a deep saturation state.

Images