This standard specifies the measurement method of the output power of high-frequency induction heating power supply devices (hereinafter referred to as power supply devices). This standard is applicable to the measurement of the output power of various induction heating power supply devices with an output frequency of high-frequency oscillators higher than 10kVz for surface and local heating quenching, heat penetration, melting and welding. JB/T 5778-1991 Measurement method of output power of high-frequency induction heating power supply devices JB/T5778-1991 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB5778-91
Measurement Method of Output Power of High-frequency Induction Heating Power Supply Device
Published on 1991-10-17
Implementation by the Ministry of Machinery and Electronics Industry of the People's Republic of China on 1992-10-01
Mechanical Industry Standard of the People's Republic of China
Measurement Method of Output Power of High-frequency Induction Heating Power Supply Device 1 Subject Content and Scope of Application
JB5778-91
This standard specifies the measurement method of output power of high-frequency induction heating power supply device (referred to as power supply device). This standard is applicable to the measurement of output power of induction heating power supply device with output frequency of high-frequency oscillator higher than 10kHz for surface and local heating quenching, heat penetration, melting and welding. 2 Reference standards
GB1800
Tolerances and fits General standard tolerances and basic deviations GB2900.23
Electrical terms Industrial electric heating equipment
ZBY270
3 Terms
Safety of electric heating equipment Part 1 General requirements Industrial glass thermometers and experimental glass thermometers Except for the following terms, the definitions of terms used in this standard can be found in GB2900.23 and Chapter 2 of GB5959.1. 3.1 High-frequency oscillator
Refers to an electronic frequency converter with an operating frequency of more than 10kHz, which is an important part of the power supply device. The common frequency is between 25kHz and 5MHz, and the output power ranges from a few watts to several megawatts. 3.2 Input power
Refers to the power obtained by the power supply device from the power supply network, which is related to the load connected to the output terminals of the high-frequency oscillator. 3.3 Rated input capacity
refers to the apparent power of the power supply device under the conditions of rated voltage, rated current and rated output power. 3.4 Output power
refers to the power absorbed by the load connected to the output terminal of the high-frequency oscillator when the power supply device is running. 3.5 Rated output power
refers to the power continuously given by the output terminal of the oscillator when the power supply device is running under rated working conditions and its output terminal is in the best matching state.
3.6 Oscillator output terminal
refers to the terminal where the high-frequency oscillator is directly connected to the inductor or connected to the inductor through a conversion link (or a relay line). The conversion link or relay line) is a component of the high-frequency oscillator. 3.7 Probe
A component of the calorimeter, which has certain measurement characteristics and material characteristics, and the high-frequency electrical energy being measured is converted into heat through it. 3.8 Electrode
refers to the conductive part used for power supply and placed in the electrolytic cell as a high-frequency resistor for measurement. The electrode is generally made of metal, and can also be made of graphite depending on the situation.
3.9 Mixing chamber
Refers to a small chamber filled with water, which is mixed to make the water temperature uniform in all parts of the room. Approved by the Ministry of Machinery and Electronics Industry on 199110-17
Implementation on 1992-10-01
Measurement method and principle
JB5778-91
When induction heating is performed, when the output frequency of the power supply device is higher than 10kHz or its power factor cos is lower than 0.5, the output power cannot be directly measured. The load of the power supply device is characterized by a complex impedance (reactance and resistance). When determining the output power of the power supply device, an equivalent method must be used, which takes into account components such as reactance and resistance (such as sensors and inductors of U-tubes). The measurement method is divided into photoelectric method and calorimetric method.
4.1 Photoelectric method
The photoelectric method is used to measure output power below 5kW. During measurement, connect an appropriate incandescent lamp H as a dummy load to the output terminal of the oscillator according to Figure 1, and tune the additional reactance element (X1 and X2) to the best impedance matching to obtain the required output power. Then measure the temperature of the incandescent lamp after the oscillator is stable. At the same time, connect a group of bulbs H2 of the same specifications and models to both ends of the adjustable voltage power supply, and adjust the voltage to make the brightness of H2 the same as H2. Measure the current and voltage flowing through the bulb H2, and the product of the current and voltage is the power consumption given by the product, which is the output power of the power supply device. For higher power, multiple incandescent lamps can be connected in series, but care must be taken to avoid possible inconsistencies in the temperature hue of each bulb, especially at high operating frequencies, which will affect the accuracy of the measurement. Considering the insulation strength and better comparability, the maximum voltage applied to these bulbs should be 70% of their rated voltage. The temperature measuring instrument shall not be affected by the interference of high-frequency electromagnetic fields. A typical temperature measuring instrument can use a colorimetric pyrometer, and the measurement error should not be greater than 5%.
Figure 1 Schematic diagram of the photoelectric method
X,, X—Additional reactance;
T-—Voltage regulating autotransformer;
U—Power supply voltage, 220V, 50Hz
In lamp current, A;
4.2. Calorimetry
The calorimetry method is used to measure output power above 1.5kW. 4.2.1 Cone calorimeter method
H, H—Incandescent lamp for comparison;
Uw-Oscillator high voltage;
Uw lamp voltage, V,.
The principle and probe structure of the cone calorimeter method are shown in Figures 2 and 3. 2
1 Water inlet,
5——Temperature sensor;
JB5778-91
Figure 2 Schematic diagram of power measurement by cone calorimeter method Temperature sensor
6—Probe:
-Bypass valve;
7 Sensor:
-Water outlet:
8—Insulated water pipe (at least 60cm long).
3 Bad of sensor
Cone calorimeter probe structure
JB5778-91
For calorimeters with heating temperature below Curie point, the probe can be made of carbon steel plate; while for calorimeters with heating temperature above Curie point, the probe can be made of brass or austenitic steel. The probe consists of a cone with a taper of 10° and a cylinder. The length of the cylinder is 1.8 times the length of the induction coil, and its diameter is determined based on the maximum allowable load of 500W per square centimeter. The size parameters of the probe are specified in Table 1. Table 1 Structural dimensions and technical parameters of cone calorimeter
Rated output power
Note: Tolerance is in accordance with the provisions of IT14 in GB1800. The sensor is wound by one or more turns of electrolytic copper tube. The inner diameter of the sensor can be up to 10mm larger than the diameter of the cylinder in the probe. The sensor and the probe should be movable relative to each other to adjust the power. The sensor and the probe should be connected in series in the same water circulation system. If necessary, a bypass valve can be added to the sensor (see Figure 2). 4.2.2 Water resistance method
This method is to place two electrodes in an insulating container through which flowing water passes, and measure the output power when the current is directly transmitted through the water. When measuring, the water resistance device and the adjustable inductor are connected in parallel to the output terminals of the oscillator. The structure of the water resistance device is shown in Figure 4.
Figure 4 Water resistance device for high-frequency power measurement
1-mixing chamber, 2-water level:
3-water outlet:
7-wiring terminal connected to the output terminal of the oscillator;-water inlet,
8-insulation adjustment plate.
-insulating container 6
-non-magnetic conductor electrode:
To avoid the formation of bubbles, the maximum load of the electrode is 200W/cm\, and the minimum spacing between the electrodes is 10mm. The larger the spacing between the electrodes, the greater the termination resistance. To facilitate power adjustment, the appropriate resistance parameters can be obtained by changing the insertion depth of the electrode in the water. Considering the maximum load that the electrode can withstand, the change can reach 1:4. The electrode should be made of non-magnetic material, such as copper or austenitic steel, the conductivity of the water should be between 300 and 500us/cm, and the capacity of the mixing chamber should not be less than 1/10 of the water flow volume per minute. The adjustable inductor is a U-shaped electrolytic copper tube, which plays the role of the reactive component of the load impedance. The minimum outer diameter of the copper tube is 8mm, and the inductance can be adjusted through a slider (see Figure 5). The inductor and the water resistor should be connected from the perspective of water supply, and in parallel from the perspective of electricity. If necessary, a bypass valve can be added to the inductor, and the nominal value of the inductance is 400nH. The relationship between the nominal size of the U-shaped adjustable inductor and the power P is specified in Table 2. When measuring, the length of the effective conductor used must be determined 1 (see Figure 5) Figure 5 Adjustable inductor
Water outlet;
5—Water inlet;
40~200
4.3 Limit value
4.3.1 Photoelectric method
Terminals connected to the output terminals of the oscillator;Terminals connected to the output terminals of the oscillator. Copper adjustable slider;
Table 2 Relationship between nominal size of adjustable inductor and power P Intermediate distance of conductor
The maximum voltage applied to the incandescent lamp should not exceed 70% of its rated voltage. 4.3. 2
Cone calorimeter method
The maximum load of the cone probe should not exceed 500W/cm\;
diameter copper tubular conductor;
The ratio of inductance to effective conductor length
The water flow rate Q is determined by the allowable power of the calorimeter and should be at least 32L/min·kW; The inlet water temperature should not exceed 35℃;
The outlet water temperature should not exceed 60C;
The inlet and outlet water temperature difference should not be less than 10℃
4.3.3 Water resistance method
The minimum spacing between electrodes is 10mm;
The electrical conductivity of water should be between 300 and 500μs/cm; The provisions on the inlet and outlet water flow and temperature are the same as those in Article 4.3.2 b to e. c.
4.4 Temperature measurement
The temperature is measured by thermocouple, thermistor or ordinary glass rod alcohol thermometer that meets ZBY270 standard, and appropriate measures should be taken to prevent it from being affected by high-frequency electromagnetic field interference. The distance between the temperature measurement point and the sensor should be 3 times the sensor diameter d. (see Figure 5
3), but the maximum should not exceed 1m.
5 Measurement
JB577891
5.1 The probe, electrode or incandescent lamp must be appropriately selected according to the output power to be measured (see Table 1 and Table 2). 5.2 The measurement must be carried out when the test equipment is in a stable working state. The water pressure and water flow must remain stable during measurement, and the measuring instrument must not be interfered by high-frequency electromagnetic fields.
5.3 The measuring point is the output terminal of the high-frequency oscillator. 6 Measurement and calculation wwW.bzxz.Net
6.1 Power calculation formula
PHp=0.06978·Q·(T,-T)~0.072Q·(TT) Where:
High frequency output power, kW,
QWater flow, L/min;
T, water inlet temperature, ℃;
—Water outlet temperature, ℃.
6.2 Accuracy of calorimeter
. The measurement error is calculated according to formula (2);
Where:
9——Deviation of the measured value of water flow;
Deviation of the measured value of temperature.
The measurement error of the calorimeter should not be greater than ±5%. Additional remarks:
This standard is proposed and managed by the National Technical Committee for Standardization of Industrial Electric Heating Equipment. This standard is drafted by Liaoning Electronic Equipment Factory and Xi'an Electric Furnace Research Institute. The main drafters of this standard are Zhong Ruizhang, Liu Xiping and Li Jingfang. 6
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60860000080060000
People's Republic of China
Mechanical Industry Standard
Measurement Method of Output Power of High Frequency Induction Heating Power Supply Device JB5778-91
Edited and published by the Standardization Research Office of the First Equipment Department of the Ministry of Machinery and Electronics Industry, the Mechanical Standardization Research Institute of the Ministry of Machinery and Electronics Industry
(Xiangtan City, Hunan Province)
Printed by Xiangtan Motor Printing Factory
Book size 880×12301/16
First edition in June 1992
Printing number
Sheet 5/8
Word count 10800
First printing in June 1992
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