What do operators need to pay attention to when conducting a variable frequency series resonance tes

During the test, the capacitance of the sample and the reactor formed a series resonant connection pattern. Capacitive voltage dividers are connected in parallel on the sample to measure the resonant voltage on the sample and monitor the overvoltage protection signal. The output of the variable frequency power supply is coupled by an excitation transformer to a series resonant circuit to provide the excitation power of the variable frequency resonant.

1.The high-frequency series resonant voltage test device should be used by high-voltage testers. Before use, read the product manual carefully and repeat the training.

2.No less than 2 operators should be used on site. When using, the safety operation procedures of the high-pressure test of the unit should be strictly observed.

3.In order to ensure the safety and correctness of the test, in addition to being familiar with the product specifications, the test operation must also be carried out in strict accordance with the relevant national standards and regulations.

4.The connecting cable must not be connected to the fault, otherwise the test set will be damaged.

5.When used in the field, the output voltage is either high voltage or ultra-high voltage. The grounding position marked by the instrument must be reliably grounded, and attention should be paid to the safety of operation.

Frequency conversion series resonant withstand voltage test device under normal circumstances, common fault causes and elimination methods.

1. Fan failure and possible causes:

1.After emergency stop, fault protection and detuning protection, there is no "fault reset";

The internal temperature is too high, the thermal protection of the power components;

Troubleshooting for fan not starting:

1.Turn off the power of the instrument, keep the instrument for about 30 minutes, restart the power supply, and press the "Reset" button on the dashboard to restart the instrument.

Second, the automatic tuning can not be completed, and the reason for the resonance point cannot be found:

The test circuit is wired incorrectly, part of the device is an open circuit, and the circuit is not well grounded;

The automatic tuning of the variable frequency series resonance withstand voltage test device cannot be completed, and the resonance point elimination method cannot be found

1.Check if the grounding device is reliable and if the grounding connection is disconnected.

2.Check the switch of the high and low voltage coils of the excitation transformer;

3.Check the on-off of each reactor;

4.Check the opening and closing of the signal line of the capacitor distributor, and check the switching of the high and low voltage capacitor arms in the voltage divider;

5。Since there is no resonance point when the device is boosted, it is necessary to check the on/off of the compensation capacitor.

Three, if all the parts are normal, there is still no reason to resonate:

The reactor does not match the sample capacity, the resonance point is not accurate, the sample loss is high, the system Q value is too low, and the high-voltage output voltage of the excitation transformer is low;

No resonance point exclusion method found:

1.The compensation capacitor is connected to the test circuit to increase the capacitance of the circuit.

2.Connect as many reactors in series as possible to increase the inductance of the loop;

3.Increase the output voltage of the excitation transformer;

4.Dry the specimen, improve the dielectric strength, and reduce the active power loss of the circuit;

Respondent: Huatian Power.

What should be paid attention to when operating the variable frequency series resonance test device?

1. The variable frequency series resonance test device should be used by high-voltage test professionals, and the instruction manual should be carefully read before use, and it should be trained by repeated operation.

2. There should be no less than 2 operators. When using the variable frequency series resonance test device, the safety operation procedures of the unit related to the high voltage test should be strictly observed.

3. In order to ensure the safety and correctness of the test, in addition to being familiar with the product manual, it must also be strictly in accordance with the country.

Relevant standards and procedures for test operations.

4. When the frequency conversion series resonance test device is used, the output is high voltage or ultra-high voltage, which must be reliably grounded and pay attention to the safety of operation.

5. When the power is turned on and the voltage is still not boosted after returning to zero, please press the reset button for a long time (about 10 seconds), and make the indicator light on the control box panel normal, that is, there is no other red light except for high voltage, and then start normal operation

6. When the voltage is greater than 10V and has not been tuned, the system will automatically detune to prevent a resonance from causing high-voltage damage to the sample and even causing harm to the human body.

7. Frequency conversion series resonance test device The connecting wires can not be connected wrong, especially the grounding wire. Failure to do so may result in damage to the test setup.

In recent years, with the rapid development of the power grid and the progress of science and technology, the power frequency withstand voltage test equipment has a small capacity, does not meet the requirements of the withstand voltage test of large electrical equipment, and is large in size, large in volume, noisy, complex in wiring, and difficult to carry. Therefore, in order to meet the development needs of the power grid, we use the series resonance test device to carry out the AC withstand voltage test on the sample, because the test is high voltage, we need to be very careful to pay attention to safety, the following introduces the use of series resonance for the test needs to pay attention to the matters?

1) We should pay attention to the field wiring: there are two places where the test line must use a special test line, can not be mixed with other test lines, one is the signal acquisition line from the voltage divider to the control host, the control host uses a coaxial signal line, and the other is an insulated high-voltage line, which is a special line connected to the bottom of the excitation transformer and the reactor. The characteristic of this insulated high-voltage line is to ensure that the line is not discharged to the ground and ensure the safe operation of the whole system.

2) How to choose the power supply: According to the equipment requirements, the power supply must be connected to AC220V or AC380V; 220 volts for power supply C terminal; 380V must be three-phase 380V, connected to the power supply inlet three-phase A, B, C; If the 380V is connected to A, the C terminal may damage the instrument, so pay attention to the power supply.

3) When the reactor is connected in parallel, the connection of the reactor is suspended end-to-end and cannot be dragged on the ground to prevent ground discharge.

4) Safety grounding: All grounding terminals on the meter must ensure safe grounding. In particular, the high-voltage tail end of the excitation transformer is easy to be overlooked.

5) In non-emergency situations, the series resonance test device cannot be depressurized and shut down by using the method of cutting off the power supply. This operation is prone to damage to the instrument. Remove the wire after discharging with a discharge rod.

These are the considerations when using series resonance. When conducting high-voltage tests, the safety principles of high-voltage tests must be followed, and the equipment shall not be operated and used without confirming the safety.

Respondent: Huatian Power.

1. Check the connection cable and confirm that it is correct.

2. Turn on the power supply: The SXBP series resonant voltage regulator console starts the "power switch" after powering on, the "power indicator" light is on, and the LCD lights up and displays.

3. Increase the output voltage of the voltage regulator: generally increase 20V to 40V.

4. Adjust the reactor clearance: (i.e., find the resonance point) Under normal circumstances, after the last test, that is, before the start of the current modulated series resonance test, the core of the adjustable reactor should be in the zero clearance position. Start to press the "increase gap" button, at this time pay attention to the value of "test voltage", in the process of adjusting the gap, the test voltage increases with the increase of the core gap, (because the increase of the gap is gradually approaching the resonance point, so the voltage also increases) when the test voltage increases to the "maximum value", (that is, when it increases to a certain point in the process of increasing the gap, the test voltage decreases), this point is the "resonance point".

5. Voltage boost: When the "resonance point" is found, the output voltage of the voltage regulator can be increased to the "rated test voltage" that needs to be added to the tested product

6. Timing: When the test voltage rises to the required value, set the "dial time relay", and the generator time is generally 1 minute; Once set, press the "Timer" button to start the timer.

7. Pressure reduction: When the withstand voltage time is completed, the voltage regulator will automatically reduce the pressure and the test will be completed (in this process, the pressure can also be manually reduced, that is, press and hold the "pressure down" button).

8. Core return: When the test is completed, the core must fall back to the "zero clearance", that is, the lowest point position, to ensure that the core mechanical transmission rod is not stressed when there is no test.

Series resonance test.

Variable frequency series resonance test is different from the general test instrument, the big feature is that the same set of equipment can be used for different electrical equipment AC withstand voltage test such as cross-linked cables, transformers, GIS, motors and generators, etc., in addition to the common models, it is usually necessary to design the configuration scheme according to the scope of the tested product and the test requirements to meet the test requirements of different regions, different users and different samples.

What do you need to know about the on-site use of variable frequency series resonance?

1. Precautions for the wiring of the excitation transformer: (1) The voltage-resistant device used for 10kV cable, the excitation transformer is generally connected to the low end; (2) It is used for the voltage-resistant device of 10kV and 35kV cables, the 10kV cable voltage-resistant excitation transformer is connected to the low end, and the 35kV cable voltage-resistant excitation transformer is connected; (3) Voltage-resistant device for 10kv, 35kv and 110kv cables: 10kV and 35kV cable voltage-resistant excitation transformer is connected to the low end, and 110kV cable voltage-resistant excitation transformer is connected.

2. Precautions for the wiring of reactors and capacitor dividers: For short cables, regardless of voltage, at least two reactors are generally connected in series to ensure that the loop can resonate.

3. Precautions for the wiring of the excitation transformer: (1) It is used for the withstand voltage device of the motor, and the excitation transformer is generally connected to the low end; (2) It is used for the voltage-resistant device of the motor and the cable, the cable's voltage-resistant excitation transformer is connected to the low end, and the motor is connected to the voltage-resistant excitation transformer; (3) In general, the resonant device used for the withstand voltage of the motor is compatible with lower voltage cables.

4. Precautions for the wiring of the excitation transformer: (1) The output voltage of the excitation transformer is generally higher for the withstand voltage device of switch, GIS and transformer; (2) Voltage-resistant device for switch and GIS, excitation transformer connection, transformer voltage-resistant excitation transformer connection to low-end; (3) Normally, this type of resonant device is compatible with shorter length cables, and the excitation transformer is connected to the low end.

5. Precautions for reactor wiring: (1) When used for switching and lower capacitance specimens AC withstand voltage test, all reactors need to be connected in series in the high-voltage circuit to ensure resonance. (2) When used for the withstand voltage of switches, GIS and transformers, the reactors need to be connected in series, and the number of reactors in series is determined according to the actual test voltage.

6. General precautions: (1) The frequency conversion series resonance test equipment should be used by high-voltage test professionals, and the instruction manual should be carefully read before use, and it should be repeatedly operated and trained. 2. There should be no less than 2 operators.

When using, it should strictly abide by the safety operation procedures of the unit related to the high-voltage test. (3) In order to ensure the safety and correctness of the test, in addition to being familiar with the product manual, the test operation must be carried out in strict accordance with the relevant national standards and procedures. (4) The connection line can not be connected wrong, otherwise it can cause damage to the test device (5) When the frequency conversion series resonance test is used, the output is high voltage or ultra-high voltage, which must be reliably grounded, and pay attention to the safety of operation.

The main precautions for frequency conversion series resonance test:

2, before the use of the equipment of the present invention and the pressure test device begins, the traffic re-check wiring is correct, such as: the field transformer (transformer) equipment (transformer) drags the voltage output cable (cable) wire connected to the lower end of the reactor at the very lowest; The upper power of the high voltage output line reactor and the upper end of a compensating capacitance divider must be kept free and not near or around objects to prevent the discharge of the material during high voltage. Because every small mistake you make will cause irreparable damage to the equipment and personnel of the enterprise.

And each correction, for on-site security personnel and equipment, will be precious;

3. For the sake of the safety of personnel and equipment, the design requirements for grounding of this device are high. When the grounding network in the substation is connected, the grounding pile, switchgear, transformer (voltage transformer) (transformer) shell dirt (soil), rust, paint, etc. should be connected in advance to ensure the effective connection between the grounding wire (also known as the lightning protection wire) and the grounding device; When there is no grounding device in the on-site operation, a metal rod about 150cm long can be selected, and the metal rod can be buried in the ground not less than 120cm to ensure that the equipment is grounded reliably.

4. The power supply of the equipment (refers to the amount of work done by the object in a unit of time) should use two live wires 380V, and the 220V power supply of the instrument should be tapped. power cords and other equipment to avoid the use of soldering to prevent interference. For example, when using a generator motor to control the power supply management work, the neutral line is grounded;

5. If the sample is discharged, the overvoltage protection of the instrument will return, which will cause damage to the instrument, although we have gone through countless simulations (definition: virtual of real things or processes) tests or set up various protections. However, this phenomenon is highly recommended for thousands of other world-wide problems during discharge, coupled with more field work equipment, transportation environments, and poorly used environments

Take shockproof and dustproof measures to transport (see solution questions) and read "Precautions".