A capacitor temperature rise test device and test method thereof

Abstract

The present invention provides a capacitor temperature rise test device and a test method thereof, belonging to the technical field of electrical detection and verification, comprising a three-phase circuit, a capacitor compensation device, a plurality of capacitors to be switched connected to the capacitor compensation device, a temperature sensor connected to the capacitor, at least one single-phase transformer, and an output circuit, wherein the capacitor compensation device has a built-in current transformer, the primary side of the single-phase transformer is connected to a phase line and a neutral line, the secondary side of the single-phase transformer is provided with the output circuit, the output circuit comprises a resistor and an inductor set according to a predetermined value, so that the power factor of the secondary side of the single-phase transformer is less than the switching threshold of the capacitor to be switched, and the secondary side of the single-phase transformer is connected in parallel to the secondary side of the current transformer. The present invention is applicable to different capacitor compensation devices, has the advantages of small size, convenient transfer, and improved detection efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of electrical detection and verification, and in particular to a capacitor temperature rise test device and a test method thereof. Background Art

[0002] Since the capacitor temperature rise test requires a reactive source to automatically switch the capacitor, the existing method is to directly force the capacitor to switch on. The disadvantage of this method is that for some intelligent capacitor compensation devices, the capacitor will automatically disconnect after a period of time and the temperature rise test cannot be completed. Another method is to add an inductive load to the capacitor group, generally a large inductor or a motor, which is not only large in size, but also causes energy waste. In addition, due to different reactive conditions in the system, different capacitive loads need to be configured, which is costly.

[0003] In view of this, the inventor specially designed a capacitor temperature rise test device and a test method thereof, and this case was thus generated. Summary of the invention

[0004] In order to solve the above problems, the technical solution of the invention is as follows:

[0005] A capacitor temperature rise test device and a test method thereof, comprising a three-phase circuit, a capacitor compensation device, a plurality of capacitors to be switched connected to the capacitor compensation device, a temperature sensor connected to the capacitor, at least one single-phase transformer, and an output circuit, wherein the capacitor compensation device has a built-in current transformer, the primary side of the single-phase transformer is connected to a phase line and a neutral line, the secondary side of the single-phase transformer is provided with an output circuit, the output circuit comprises a resistor and an inductor set according to predetermined values, so that the power factor of the secondary side of the single-phase transformer is less than a switching threshold of the capacitor to be switched, and the secondary side of the single-phase transformer is connected in parallel to the secondary side of the current transformer.

[0006] Preferably, three single-phase transformers are provided, and one end of the primary side of the three single-phase transformers is respectively connected to the three phase lines in the three-phase circuit, and the other end is connected to the neutral line.

[0007] Preferably, the capacitance compensation device has a three-phase power factor meter, and the primary side of the current transformer is connected to the three-phase power factor meter.

[0008] Preferably, the switching threshold of the capacitor to be switched is 0.7.

[0009] Preferably, the secondary side voltage of the single-phase transformer is 12V, the resistance is 2 ohms, the inductance is 15mH, and the power factor of the secondary side of the single-phase transformer is 0.5.

[0010] Preferably, the resistor is a fixed-resistance resistor or an adjustable resistor.

[0011] Preferably, the output circuit also includes an ammeter and a fuse.

[0012] A capacitor temperature rise test method, the specific operation steps are:

[0013] a. Connect the primary side of the single-phase transformer to the three-phase circuit, and set the output circuit on the secondary side of the single-phase transformer;

[0014] b. Connect the capacitor to be switched to the capacitor compensation device;

[0015] c. Connect the secondary side of the single-phase transformer to the secondary side of the current transformer;

[0016] d. The capacitors are switched on and off successively and run continuously, and the temperature of the capacitors will be displayed on the temperature sensor;

[0017] e. Compare the temperature rise of the capacitor after running for a specified time with the standard to complete the capacitor temperature rise test.

[0018] The present invention comprises a three-phase circuit, a capacitor compensation device, a plurality of capacitors to be switched connected to the capacitor compensation device, a single-phase transformer, and an output circuit. The capacitor compensation device has a built-in current transformer. The primary side of the single-phase transformer is connected to a phase line and a neutral line. The secondary side of the single-phase transformer is provided with an output circuit. The output circuit comprises a resistor and an inductor set according to a predetermined value, so that the power factor of the secondary side of the single-phase transformer is less than the switching threshold of the capacitor to be switched, and the secondary side of the single-phase transformer is connected in parallel to the secondary side of the current transformer. Compared with conventional large inductors and large motors, the device is smaller in size and easier to transfer. Due to the difference in principle, it can be adapted to all capacitor compensation devices. The capacitor compensation device has a built-in three-phase power factor meter, which can be compared with a reactive power controller on a test product, so as to facilitate the detection of the problem that the capacitor group is not switched. At the same time, for a capacitor compensation device with a built-in simulation function, only a small-capacity power supply is required when using the device to complete a capacitor overvoltage test. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide further understanding of the invention and constitute a part of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute improper limitations on the invention.

[0020] in:

[0021] Figure 1 is a circuit diagram of the present invention;

[0022] Figure 2 The present invention Figure 1 Schematic diagram of the amplification circuit in the middle A area;

[0023] Figure 3 It is a circuit schematic diagram of the present invention;

[0024] Figure 4It is a flow chart of the steps of the capacitor temperature rise test method of the present invention.

[0025] Description of labels:

[0026] 1. Three-phase circuit; 2. Capacitor compensation device; 21. Current transformer; 22. Three-phase power factor meter; 3. Capacitor; 31. Temperature sensor; 4. Single-phase transformer; 5. Output circuit; 51. Resistance; 52. Inductance; 53. Ammeter; 54. Fuse. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects to be solved by the invention clearer and more understandable, the invention is further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and are not used to limit the invention.

[0028] See also Figures 1 to 4 , is a capacitor temperature rise test device and test method as the best embodiment of the invention, comprising a three-phase circuit 1, a capacitor compensation device 2, a plurality of capacitors to be switched 3 connected to the capacitor compensation device 2, a temperature sensor 31 connected to the capacitor 3, at least one single-phase transformer 4, and an output circuit 5, wherein the capacitor compensation device 2 has a built-in current transformer 21, the primary side of the single-phase transformer 4 is connected to the phase line and the neutral line, and the secondary side of the single-phase transformer 4 is provided with the output circuit 5;

[0029] The compensation principle of capacitor 3 is as follows: the power output by the power grid includes two parts, including active power and reactive power. Among them, the power that directly consumes electric energy, converts electric energy into mechanical energy, heat energy, chemical energy or sound energy, and uses these energies to do work is called active power; the power that does not consume electric energy, but converts electric energy into another form of energy, which is a necessary condition for electrical equipment to do work, and this energy is periodically converted with electric energy in the power grid, and this part of power is called reactive power, such as the electric energy occupied by electromagnetic components to establish a magnetic field, and the electric energy occupied by capacitor 3 to establish an electric field. When the current works in the inductor 52 element, the current lags behind the voltage by 90°; and when the current works in the capacitor 3 element, the current leads the voltage by 90°. In the same circuit, the current of the inductor 52 is opposite to the current of the capacitor 3, and the difference is 180°. If capacitors are installed proportionally in the electromagnetic circuit so that their currents cancel each other out, the angle between the current vector and the voltage vector can be reduced, which can increase the active power of the grid, reduce line energy loss, improve the system's power supply capacity, reduce line voltage drop, and improve the grid voltage quality.

[0030] In addition, the switching mode of capacitor 3 can select the corresponding switching setting according to the selected switching type. Different switching types cannot compare the setting. For example, according to the time type, you can choose to start from 8:00 to 12:00 and stop from 12:00 to 14:00; according to the power factor type, you can choose to start when it is lower than 0.8 and stop when it is higher than 0.8; according to the reactive power demand, it will start when the shortage is 300 to 500kvar and stop when it exceeds 100kvar;

[0031] This embodiment adopts the type of power factor to set the switching of the capacitor 3. The output circuit 55 includes a resistor 51 and an inductor 52 set according to predetermined values, so that the power factor of the secondary side of the single-phase transformer 4 is less than the switching threshold of the capacitor 3 to be switched, and the secondary side of the single-phase transformer 4 is connected in parallel to the secondary side of the current transformer 21.

[0032] like Figure 1 As shown, three single-phase transformers 44 are provided, and one end of the primary side of the three single-phase transformers 44 is respectively connected to Ua, Ub, and Uc of the three phase lines in the three-phase circuit 11, and the other end is connected to the neutral line.

[0033] like Figure 1 As shown, the capacitance compensation device 2 has a three-phase power factor meter 22 , and the primary side of the current transformer 21 is connected to the three-phase power factor meter 22 .

[0034] like Figure 2 As shown, in this embodiment, the switching threshold of the capacitor 3 to be switched is set to 0.7, and the secondary side voltage of the single-phase transformer 4 is 12V, the resistor 51 is 2 ohms, wherein the resistor 51 can be any one of a fixed resistance resistor or an adjustable resistor, and the inductor 52 is 15mH, so that the power factor of the secondary side of the single-phase transformer 4 is maintained at 0.5. Because the power factor 0.5 is less than 0.7 of the capacitor 3 to be switched, it can ensure that all the capacitors 3 are switched. Compared with the forced switching of the capacitor 3, the temperature rise test of the capacitor 3 can be stably and automatically realized.

[0035] like Figure 2 As shown, the output circuit 5 also includes an ammeter 53 and a fuse 54. The ammeter 53 can be used to monitor the current of the output circuit 5 in real time, and can be used to compare with the three-phase power factor meter, so as to easily find out the problem of the capacitor 3 not being switched on and off, and make subsequent adjustments; the specific rated limit current of the fuse 54 is 10A, which is used to prevent damage to the equipment caused by line overload.

[0036] See also Figure 4 , is a flow chart of the steps of the capacitor temperature rise test method of the present invention, and the specific operation steps are:

[0037] a. Connect the primary side of the single-phase transformer 4 to the three-phase circuit 1, and set the output circuit 5 on the secondary side of the single-phase transformer 4;

[0038] b. Connect the capacitor 3 to be switched to the capacitor compensation device 2;

[0039] c. Connect the secondary side of the single-phase transformer 4 to the secondary side of the current transformer 21;

[0040] d. Capacitor 3 is switched on and off successively and operates continuously, and the temperature of capacitor 3 is displayed on temperature sensor 31;

[0041] e. Compare the temperature rise of capacitor 3 after running for a specified time with the standard to complete the temperature rise test of capacitor 3.

[0042] The present invention comprises a three-phase circuit 1, a capacitor compensation device 2, a plurality of capacitors 3 to be switched connected to the capacitor compensation device 2, a single-phase transformer 4, and an output circuit 5. The capacitor compensation device 2 has a built-in current transformer 21. The primary side of the single-phase transformer 4 is connected to the phase line and the neutral line. The secondary side of the single-phase transformer 4 is provided with the output circuit 5. The output circuit 5 comprises a resistor 51 and an inductor 52 set according to a predetermined value, so that the power factor of the secondary side of the single-phase transformer 4 is less than the switching threshold of the capacitor 3 to be switched, and the secondary side of the single-phase transformer 4 is connected in parallel to the secondary side of the current transformer 21. Compared with conventional large inductors 52 and large motors, this device is smaller in size and easier to transfer. Due to the difference in principle, it can be adapted to all capacitor compensation devices 2. The capacitor compensation device 2 has a built-in three-phase power factor meter 22, which can be compared with a reactive power controller on a test product, so as to facilitate the detection of the problem that the capacitor 3 group is not switched. At the same time, for the capacitor compensation device 2 with a built-in simulation function, only a small capacity power supply is required when using this device to complete the capacitor 3 overvoltage test.

[0043] In summary, the present invention can automatically realize continuous switching of the capacitor 3 through the output circuit 5, is applicable to different capacitor compensation devices 2, has the advantages of small size, convenient transfer, and improved detection efficiency.

[0044] The invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the invention, or the concept and technical solution of the invention are directly applied to other occasions without improvement, they are all within the scope of protection of the invention.

Claims

1. A capacitor temperature rise test device, characterized in that: The invention comprises a three-phase circuit (1), a capacitor compensation device (2), a plurality of capacitors (3) to be switched connected to the capacitor compensation device (2), a temperature sensor (31) connected to the capacitor (3), at least one single-phase transformer (4), and an output circuit (5); the capacitor compensation device (2) has a built-in current transformer (21); the primary side of the single-phase transformer (4) is connected to a phase line and a neutral line; the secondary side of the single-phase transformer (4) is provided with the output circuit (5); the output circuit (5) comprises a resistor (51) and an inductor (52) set according to predetermined values, so that the power factor of the secondary side of the single-phase transformer (4) is less than the switching threshold of the capacitor (3) to be switched, and the secondary side of the single-phase transformer (4) is connected in parallel to the secondary side of the current transformer (21); the resistor (51) is any one of a fixed resistance resistor and an adjustable resistor; and the output circuit (5) comprises an ammeter (53) and a fuse (54).

2. A capacitor temperature rise test device according to claim 1, characterized in that: A total of three single-phase transformers (4) are provided, and one end of the primary side of the three single-phase transformers (4) is respectively connected to the three phase lines in the three-phase circuit (1), and the other end is connected to the neutral line.

3. A capacitor temperature rise test device according to claim 1, characterized in that: The capacitance compensation device (2) has a three-phase power factor meter (22), and the primary side of the current transformer (21) is connected to the three-phase power factor meter (22).

4. A capacitor temperature rise test device according to claim 1, characterized in that: The switching threshold of the capacitor (3) is 0.

7.

5. A capacitor temperature rise test device according to claim 4, characterized in that: The secondary side voltage of the single-phase transformer (4) is 12V, the resistance (51) is 2 ohms, the inductance (52) is 15 mH, and the power factor of the secondary side of the single-phase transformer (4) is 0.

5.

6. A capacitor temperature rise test method, characterized in that: Used for a capacitor temperature rise test device according to any one of claims 1 to 5, the specific operating steps are: a. connecting the primary side of the single-phase transformer (4) to the three-phase circuit (1), and arranging the output circuit (5) on the secondary side of the single-phase transformer (4); b. connecting the capacitor (3) to be switched on to the capacitor compensation device (2); c. connecting the secondary side of the single-phase transformer (4) to the secondary side of the current transformer (21); d. The capacitor (3) is switched on and off successively and operates continuously, and the temperature of the capacitor (3) is displayed on the temperature sensor (31); e. Compare the temperature rise of the capacitor (3) after running for a specified time with the standard to complete the temperature rise test of the capacitor (3).

Images