A temperature rise test method for medium voltage switchgear with adjustable simulated ambient temperature

Abstract

The present invention relates to a medium voltage switch temperature rise test, in particular to a medium voltage switch device temperature rise test method with adjustable simulated ambient temperature, at least comprising: a temperature rise test equipment unit 1, a constant temperature simulation box 2, and a temperature rise automatic measurement unit 3; the temperature rise test equipment unit 1 provides a test power supply 6 connected to a switch test piece 4 at the center of the constant temperature simulation box unit 2 through a silicone sleeve 5, and the temperature rise automatic measurement unit 3 controls the temperature rise of the constant temperature simulation box unit 2 and performs temperature control and measurement on the switch test piece 4; the present invention connects the test power supply to the constant temperature simulation test box through a silicone sleeve with good thermal insulation performance. The space inside the constant temperature simulation test box meets the temperature rise test requirements of medium voltage switch products, and the box body is made of a polyurethane panel with good thermal insulation performance. The temperature rise of the switch device in the simulated infinite space and specific temperature is controlled, and the temperature and wind speed are controlled.

Description

Technical Field

[0001] The present invention relates to a medium-voltage switch temperature rise test, and in particular to a medium-voltage switchgear temperature rise test method with adjustable simulated ambient temperature, which is mainly used to simulate the temperature rise test characteristics of 3.6~40.5kV medium-voltage AC metal-enclosed switchgear at a specific ambient temperature as described in GB / T 3906-2020, and is particularly suitable for studying the temperature rise characteristics of a test piece at a high ambient temperature with poor heat dissipation conditions. Background Art

[0002] Existing medium-voltage switch temperature rise units mostly use large current generating devices to perform temperature rise tests and temperature measurements at room temperature. They cannot simulate the temperature rise of switchgear in an infinite space and at a specific temperature, and therefore cannot improve equipment reliability. Summary of the invention

[0003] The purpose of the present invention is to provide a temperature rise test method for medium voltage switchgear in a high temperature environment, so as to simulate the temperature rise of switchgear in an infinite space and at a specific temperature, and to realize temperature control and wind speed control according to the needs of the test unit, thereby improving the reliability of the medium voltage switch.

[0004] The object of the present invention is achieved in this way. A temperature rise test method for medium-voltage switchgear under high temperature environment is characterized in that it at least comprises: a temperature rise test equipment unit 1, a constant temperature simulation box 2, and a temperature rise automatic measurement unit 3; the temperature rise test equipment unit 1 provides a test power supply 6 connected to the switch test piece 4 at the center of the constant temperature simulation box unit 2 through a silicone sleeve 5, and the temperature rise automatic measurement unit 3 controls the temperature rise of the constant temperature simulation box unit 2 and performs temperature control measurement on the switch test piece 4; The constant temperature simulation box unit 2 includes: a constant temperature box 201, a constant temperature heating unit 202, a refrigeration unit 203, and an electric circulation heater 204. The constant temperature heating unit 202, the refrigeration unit 203, and the electric circulation heater 204 are connected to the constant temperature box 201 through the pipeline valve pipeline; the constant temperature heating unit 202, the refrigeration unit 203, and the electric circulation heater 204 are comprehensively controlled by the controller to make the constant temperature box 201 produce a set constant temperature; The temperature rise automatic measurement unit 3 includes a temperature measuring element thermocouple and a measurement and control unit. The thermocouples are distributed in the constant temperature simulation box 2. Each thermocouple is electrically connected to the detection port of the measurement and control unit. The measurement and control unit is electrically connected to the constant temperature simulation box 2 through the output control port. The above-mentioned temperature control measurement of the switch test piece 4 includes the following steps: the heating unit is put into operation in advance, the heating plates are heated in groups, and when the temperature is close to 50°C, the temperature control is started according to the ambient temperature groups; when the temperature is higher than the required temperature, the refrigeration unit is operated, the water temperature of the chiller is 0-3°C, and heat is absorbed by controlling the cold water flow; at the same time, it is used to absorb heat during the test to simulate the heat absorption process of the air in the infinite space test piece; during the test, the auxiliary heating heater and the refrigeration unit are operated to stabilize the temperature of the constant temperature box at around 50±2°C to meet the constant temperature requirement.

[0005] The temperature rise test equipment unit 1 is composed of a large current transformer 101, a current regulating unit 102 and a voltage regulator 103. The temperature rise test equipment unit 1 is divided into an AC temperature rise device and a DC temperature rise device. The AC temperature rise device or the DC temperature rise device 105 provides a detection power supply 6 to the switch test product 4 through the large current transformer 101, the current regulating unit 102 and the voltage regulator 103 via the busbar 104. The voltage regulator 103 is designed according to the test load of the AC temperature rise device or the DC temperature rise device. The secondary output of the voltage regulator 103 provides the required current and voltage to the AC temperature rise device and the DC temperature rise device.

[0006] The constant temperature box 201 is 4.5 meters long, 3.5 meters wide and 5 meters high. The constant temperature box 201 adopts hinged doors with a door opening width of 2500mm and a height of 4000mm. It is equipped with a safety door locking mechanism and an electric heating anti-condensation hollow observation window on the door.

[0007] The refrigeration unit 203 uses a circulating water cooling heat exchanger, which is evenly distributed on the side wall of the box, and the circulating cooling water is connected to the constant temperature box 201 through a DN20 hose. The power of the chiller is 10kW.

[0008] There are two sets of constant temperature heating units 202, one set is the main heater, located on the top of the constant temperature box 201, it uses a resistance heating circulation fan with a total power of 90kW; the other set is an auxiliary heater, it uses an electric heating auxiliary heating plate, it is closely distributed on both sides of the box wall of the box 201, and the power is 15kW.

[0009] The heat circulation fan adopts non-magnetic nickel-chromium wire to heat the air as the hot air source and adopts PID / SSR control.

[0010] The constant temperature heating unit 202 and the electric circulation heater 204 together constitute the thermal control system of the constant temperature box 201. The heat circulation fan, heating plate and circulating water cooling heat exchanger are distributed at intervals on the wall of the constant temperature box 201. The wall of the constant temperature box 201 is made of insulation material. The main material of the box wall is 100 thick polyurethane panel, with 4 mm thick 304 stainless steel attached to the outside.

[0011] The heat cycle fan parameters include: Table 2 Technical parameters of heat cycle fan equipment unit project Technical Parameters Heating power 90kW Fan power 11kW Input voltage 380V Maximum wind pressure 7100Pa Maximum air volume 3600m³ / h Maximum temperature 350℃ Temperature control accuracy ±1℃ The technical parameters of the circulating water cooling heat exchanger are: Table 3 Technical parameters of circulating water cooling heat exchanger equipment unit project Technical Parameters Cooling capacity 10kW Water temperature control range 0.5-10℃ Input voltage 380V refrigerant r22 Water tank capacity 100L Water pump power 750W Pump head range 0～10m Pump flow range 8~58L / m Temperature control accuracy ±1℃ The controller controls the constant temperature heating unit 202, the refrigeration unit 203, and the electric circulation heater 204 to make the constant temperature box 201 produce the set constant temperature. The process is as follows: ①Install the medium voltage switch test piece and its sensor; ② Use the main circulation heating fan to heat the space as a whole; ③ Make the ambient temperature reach 50±2℃; ④When the temperature reaches the requirement, stop the main fan to make the wind speed meet the requirement; ⑤During the test, start the auxiliary heat or cold heat exchanger to balance the heating of the test sample and maintain a constant temperature in the environmental chamber; ⑥Perform temperature test; ⑦Record the data and end the test.

[0012] Advantages and specific solutions of the present invention:

[0013] 1. Use a limited box to simulate the ambient temperature of the actual large space where the equipment is installed.

[0014] a. Considering the manufacturing cost and the maximum test product size, the clearance size of the test box is selected as 3.5×4.5×5m (h). Its volume is about 5 times the volume of the test product, which is conducive to ensuring that the heat dissipation of the test product is not affected.

[0015] b. Control of surrounding wind speed. Since there are requirements for the surrounding air wind speed during the temperature rise test, which is generally required to be ≤0.5m / s, the design of this device considers the use of a resistance heater + fan circulation method in the first heating stage to increase the box temperature to 95% of the required ambient temperature of the test product (such as 50°C, increased to 47.5°C). The use of fan circulation is conducive to quickly ensuring the uniform temperature inside the box, but the wind speed will exceed 0.5m / s. After the goals of the previous stage are achieved, the constant temperature stage is entered. In this stage, the fan is turned off, and the ambient temperature is heated to the final required ambient temperature and maintained at a constant temperature by controlling the electric heating radiation panel and the circulating water cooling device. This process is conducive to controlling the wind speed to meet ≤0.5m / s.

[0016] c. Consideration of the cooling power of the chiller. First, it is necessary to consider balancing the heat generation power of the test product (maximum about 10kW) to ensure that the ambient air temperature is constant and evenly distributed around the experimental box; second, it is necessary to ensure the dynamic balance of the box temperature, which is jointly adjusted by the electric heating radiation plate and the circulating water heat exchanger to ensure that the temperature control accuracy is ±0.5℃.

[0017] 2. For the selection of the box, choose the finished foamed polyurethane panel with good heat resistance and low thermal conductivity, whose thermal conductivity is about 0.018-0.023 W / (m·k). Considering the thermal insulation performance and mechanical strength, the thickness is 100mm, and the two sides are protected by 4mm thick stainless steel, which is anti-collision, anti-corrosion, and conducive to thermal insulation and energy saving.

[0018] 3. Matching test power supply device. The AC current source and multi-channel measurement unit are introduced through the bushing to meet the temperature rise current needs and measurement accuracy requirements of the test product. The current terminal and the measurement terminal are introduced through the thermal insulation sealing bushing.

[0019] The present invention connects the test power supply to the constant temperature simulation test box through a silicone sleeve with good thermal insulation performance. The space inside the constant temperature simulation test box meets the temperature rise test requirements of medium voltage switch products. The box body is made of polyurethane panels with good thermal insulation performance. The temperature rise of the switch equipment under the simulation of infinite space and specific temperature is controlled, and the temperature and wind speed are controlled.

[0020] The present invention will be further described below in conjunction with the accompanying drawings of the embodiments: BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the composition of an embodiment of the present invention; Figure 1A It is the schematic diagram of the temperature rise test equipment unit; Figure 2 Schematic diagram of the composition of the constant temperature simulation box unit; Figure 2A Provide the specific shape and size of the constant temperature box 201; Figure 2B A door opening structure diagram of the constant temperature box 201 is provided; Figure 2C A temperature control structure diagram in the constant temperature box 201 is given.

[0022] Figure 3 Schematic diagram of the composition of the constant temperature simulation box unit; Figure 4 Process logic diagram; Figure 5A The main control principle diagram of the temperature control logic of the constant temperature simulation box; Figure 5B Schematic diagram of the constant temperature control logic of the constant temperature simulation box.

[0023] In the figure, 1. test equipment unit; 2. constant temperature simulation box unit; 3. temperature rise automatic measurement unit; 4. medium voltage switch test piece; 5. silicone casing; 6. power supply. DETAILED DESCRIPTION

[0024] like Figure 1 As shown, a temperature rise test method for medium-voltage switchgear under high temperature environment is characterized in that it includes at least: a temperature rise test equipment unit 1, a constant temperature simulation box 2, and a temperature rise automatic measurement unit 3; the temperature rise test equipment unit 1 provides a test power supply 6 which is connected to the switch test piece 4 at the center of the constant temperature simulation box unit 2 through a silicone sleeve 5, and the temperature rise automatic measurement unit 3 controls the temperature rise of the constant temperature simulation box unit 2 and performs temperature control measurement on the switch test piece 4.

[0025] like Figure 1A As shown, the temperature rise test equipment unit 1 is composed of a large current transformer 101, a current regulating unit 102 and a voltage regulator 103. The temperature rise test equipment unit 1 is divided into an AC temperature rise device and a DC temperature rise device. The AC temperature rise device or the DC temperature rise device 105 provides a detection power supply 6 to the switch test product 4 through the large current transformer 101, the current regulating unit 102 and the voltage regulator 103 via the busbar 104. The voltage regulator 103 is designed according to the test load of the AC temperature rise device or the DC temperature rise device. The secondary output of the voltage regulator 103 provides the required current and voltage to the AC temperature rise device and the DC temperature rise device.

[0026] like Figure 2 As shown, the constant temperature simulation box unit 2 includes: a constant temperature box 201, a constant temperature heating unit 202, a refrigeration unit 203, and an electric circulation heater 204. The constant temperature heating unit 202, the refrigeration unit 203, and the electric circulation heater 204 are connected to the constant temperature box 201 through the pipeline valve pipeline. The constant temperature box 201 generates a set constant temperature through the comprehensive control of the constant temperature heating unit 202, the refrigeration unit 203, and the electric circulation heater 204 by the controller.

[0027] The following will Figure 2 It is divided into three parts for explanation: Figure 2A Provide the specific shape and size of the constant temperature box 201; Figure 2B A door opening structure diagram of the constant temperature box 201 is provided; Figure 2C A temperature control structure diagram in the constant temperature box 201 is given.

[0028] like Figure 2A As shown, the constant temperature box 201 is 4.5 meters long, 3.5 meters wide and 5 meters high.

[0029] like Figure 2BAs shown, the constant temperature box 201 adopts hinged double doors, the door opening width is 2500mm, the height is 4000mm, it is equipped with a safety door locking mechanism, and the door is equipped with an electric heating anti-condensation hollow observation window.

[0030] like Figure 2 -C view shows the distribution diagram of circulating water cooling heat exchanger, fan and heating plate. The refrigeration unit 203 adopts circulating water cooling heat exchanger, which is evenly distributed on the side wall of the box. The circulating cooling water is connected to the constant temperature box 201 through a DN20 hose. The chiller power is 10kW.

[0031] There are two sets of constant temperature heating units 202, one set is the main heater, located at the top of the constant temperature box 201, it uses a resistance heating circulation fan with a total power of 90kW. The other set is an auxiliary heater, which uses an electric heating auxiliary heating plate, which is closely distributed on both sides of the box wall of the box 201, and has a power of 15kW.

[0032] The heat circulation fan adopts non-magnetic nickel-chromium wire to heat the air as the hot air source, adopts PID / SSR control, and has the advantages of high precision, fast feedback and durability.

[0033] like Figure 2B and Figure 2C As shown, the constant temperature heating unit 202 and the electric circulation heater 204 together constitute the thermal control system of the constant temperature box 201. The heat circulation fan, the heating plate and the circulating water cooling heat exchanger are distributed on the wall of the constant temperature box 201 at intervals. The wall of the constant temperature box 201 is made of insulation material. The main material of the box wall is 100 thick polyurethane panel, and 4mm thick 304 stainless steel is attached. The polyurethane panel has a low thermal conductivity of 0.018 to 0.023 W / (m·k). The polyurethane panel is fireproof, flame retardant, high temperature resistant, and has excellent thermal insulation performance. Under the same insulation requirements, the use area can be increased.

[0034] The heat cycle fan parameters include: Table 2 Technical parameters of heat cycle fan equipment unit project Technical Parameters Heating power 90kW Fan power 11kW Input voltage 380V Maximum wind pressure 7100Pa Maximum air volume 3600m³ / h Maximum temperature 350℃ Temperature control accuracy ±1℃ The technical parameters of the circulating water cooling heat exchanger are: Table 3 Technical parameters of circulating water cooling heat exchanger equipment unit project Technical Parameters Cooling capacity 10kW Water temperature control range 0.5-10℃ Input voltage 380V refrigerant r22 Water tank capacity 100L Water pump power 750W Pump head range 0～10m Pump flow range 8~58L / m Temperature control accuracy ±1℃ The main material of the box wall is 100mm thick polyurethane panel, with 4mm thick 304 stainless steel attached. The thermal conductivity of polyurethane panel is low, with a thermal conductivity of 0.018-0.023 W / (m·k). Polyurethane panel is fireproof, flame retardant, high temperature resistant, and has excellent thermal insulation performance. Under the same insulation requirements, the use area can be increased.

[0035] like Figure 3 As shown, the temperature rise automatic measurement unit 3 includes a temperature measuring element thermocouple and a measurement and control unit. The thermocouples are distributed in the constant temperature simulation box 2. Each thermocouple is electrically connected to the detection port of the measurement and control unit. The measurement and control unit is electrically connected to the constant temperature simulation box 2 through the output control port.

[0036] The main heating unit is put into operation in advance, and the heating plates are grouped. When the temperature is close to 50℃, they are grouped according to the ambient temperature to accurately control the temperature. When the temperature is higher than the required temperature, the refrigeration unit works, and the water temperature of the chiller is (0-3℃), and heat is absorbed by controlling the cold water flow. At the same time, it is used to absorb heat during the test to simulate the heat absorption process of the air in the infinite space test product. During the test, the auxiliary heater and the refrigeration unit work to stabilize the temperature of the thermostat at around 50±2℃, meeting the constant temperature requirements.

[0037] like Figure 4 The controller controls the constant temperature heating unit 202, the refrigeration unit 203, and the electric circulation heater 204 to make the constant temperature box 201 produce the set constant temperature. The process is as follows: ①Install the medium voltage switch test piece and its sensor; ② Use the main circulation heating fan to heat the space as a whole; ③ Make the ambient temperature reach 50±2℃; ④When the temperature reaches the requirement, stop the main fan to make the wind speed meet the requirement; ⑤During the test, start the auxiliary heat or cold heat exchanger to balance the heating of the test sample and maintain a constant temperature in the environmental chamber; ⑥Perform temperature test; ⑦Record the data and end the test.

[0038] Test equipment unit 1. Includes AC temperature rise equipment and DC temperature rise equipment to provide stable high current testing.

[0039] like Figure 5A and Figure 5B As shown, Figure 5A Thermostatic simulation box temperature control logic schematic diagram, Figure 5B This is the temperature control logic schematic of the constant temperature simulation box.

[0040] like Figure 5A As shown, during the time t1, the main heater heats up, and the temperature inside the box rises from the ambient temperature to around 50±2℃. According to the feedback from the temperature measuring unit, the auxiliary heater or refrigeration unit is put into operation during the test period t1-t2.

[0041] like Figure 5BAs shown in the figure, the main temperature control logic is: the main heating unit is put into operation in advance, and the heating plates are grouped. When the temperature is close to 50°C, they are grouped according to the ambient temperature to accurately control the temperature. When the temperature is higher than the required temperature, the refrigeration unit works, and the water temperature of the chiller is (0-3°C), and heat is absorbed by controlling the cold water flow. At the same time, it is used to absorb heat during the test to simulate the heat absorption process of the air in the infinite space test product. During the test, the auxiliary heater and the refrigeration unit work to stabilize the temperature of the thermostat at around 50±2°C, meeting the constant temperature requirements.

Claims

1. A temperature rise test method for medium voltage switchgear in a high temperature environment, characterized in that at least include: A temperature rise test equipment unit (1), a constant temperature simulation box unit (2), and a temperature rise automatic measurement unit (3); the temperature rise test equipment unit (1) provides a test power supply (6) which is connected to a switch test piece (4) at the center of the constant temperature simulation box unit (2) through a silicone sleeve (5); the temperature rise automatic measurement unit (3) controls the temperature rise of the constant temperature simulation box unit (2) and performs temperature control measurement on the central switch test piece (4); The constant temperature simulation box unit (2) comprises: a constant temperature box (201), a constant temperature heating unit (202), a refrigeration unit (203), and an electric circulation heater (204); the constant temperature heating unit (202), the refrigeration unit (203), and the electric circulation heater (204) are connected to the constant temperature box (201) through a pipeline valve pipeline; the constant temperature heating unit (202), the refrigeration unit (203), and the electric circulation heater (204) are comprehensively controlled by a controller to enable the constant temperature box (201) to generate a set constant temperature; The temperature rise automatic measurement unit (3) comprises a temperature measuring element thermocouple and a measurement and control unit, the thermocouples are distributed in the constant temperature simulation box unit (2), each thermocouple is electrically connected to a detection port of the measurement and control unit, and the measurement and control unit is electrically connected to the constant temperature simulation box unit (2) via an output control port; The above-mentioned temperature control measurement of the medium voltage switch test piece (4) comprises the following steps: The heating unit is put into operation in advance, and the heating plates are heated in groups. When the temperature approaches 50°C, the temperature control is started according to the ambient temperature groups. When the temperature is higher than the required temperature, the refrigeration unit works, and the water temperature of the chiller is 0-3°C, and heat is absorbed by controlling the cold water flow. At the same time, it is used to absorb heat during the test to simulate the heat absorption process of the air in the infinite space test product. During the test, the auxiliary heater and the refrigeration unit work to stabilize the temperature of the constant temperature box at around 50±2°C, meeting the constant temperature requirement.

2. A temperature rise test method for medium voltage switchgear in a high temperature environment according to claim 1, characterized in that: The temperature rise test equipment unit (1) is composed of a large current transformer (101), a current regulating unit (102) and a voltage regulator (103). The temperature rise test equipment unit (1) is divided into an AC temperature rise equipment and a DC temperature rise equipment. The AC temperature rise equipment or the DC temperature rise equipment (105) provides a detection power supply (6) to a switch test piece (4) via a busbar (104) through the large current transformer (101), the current regulating unit (102) and the voltage regulator (103). The voltage regulator (103) is designed according to the test load of the AC temperature rise equipment or the DC temperature rise equipment. The secondary output of the voltage regulator (103) provides the required current and voltage to the AC temperature rise equipment or the DC temperature rise equipment.

3. A temperature rise test method for medium voltage switchgear in a high temperature environment according to claim 1, characterized in that: The constant temperature box (201) is 4.5 meters long, 3.5 meters wide and 5 meters high. The constant temperature box (201) adopts hinged double doors with a door opening width of 2500 mm and a height of 4000 mm. It is equipped with a safety door locking mechanism and an electric heating anti-condensation hollow observation window on the door. The refrigeration unit (203) adopts a circulating water cooling heat exchanger, which is evenly distributed on the side wall of the box body. The circulating cooling water is connected to the constant temperature box body (201) through a DN20 hose, and the chiller power is 10kW; There are two sets of constant temperature heating units (202), one set is a main heater, located on the top of the constant temperature box (201), it uses a resistance heating circulation fan with a total power of 90kW; the other set is an auxiliary heater, it uses an electric heating auxiliary heating plate, it is closely distributed on both sides of the box wall of the box (201), and the power is 15kW; the heat circulation fan uses a non-magnetic nickel-chromium wire to heat the air as a hot air source, and adopts PID / SSR control.

4. A temperature rise test method for medium voltage switchgear in a high temperature environment according to claim 1, characterized in that: The constant temperature heating unit (202) and the electric circulation heater (204) together constitute the thermal control system of the constant temperature box (201); the heat circulation fan, the heating plate and the circulating water cooling heat exchanger are distributed at intervals on the wall of the constant temperature box (201); the wall of the constant temperature box (201) is made of insulation material, and the main material of the box wall is 100 thick polyurethane panel, with 4 mm thick 304 stainless steel attached to the outside.

5. A temperature rise test method for medium voltage switchgear in a high temperature environment according to claim 1, characterized in that: The parameters of the heat cycle fan include: Table 2 Technical parameters of heat cycle fan equipment unit 6. A temperature rise test method for medium voltage switchgear in a high temperature environment according to claim 1, characterized in that: The technical parameters of the circulating water cooling heat exchanger are: Table 3 Technical parameters of circulating water cooling heat exchanger equipment unit 7. A temperature rise test method for medium voltage switchgear in a high temperature environment according to claim 1, characterized in that: The constant temperature box (201) generates a set constant temperature through the comprehensive control of the constant temperature heating unit (202), the refrigeration unit (203) and the electric circulation heater (204) by the controller. The process is as follows: ① Install the medium voltage switch test piece (4) and its sensor; ② Use the main circulation heating fan to heat the space as a whole; ③ Make the ambient temperature reach 50±2℃; ④When the temperature reaches the requirement, stop the main fan to make the wind speed meet the requirement; ⑤During the test, start the auxiliary heat or cold heat exchanger to balance the heating of the test sample and maintain a constant temperature in the environmental chamber; ⑥Perform temperature test; ⑦Record the data and end the test.

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