1. For fans and pumps, select the appropriate frequency converter according to the rated voltage/rated current/rated power of the motor; for the constant power load such as the belt conveyor, select the frequency converter suitable for the operating characteristics according to the load conditions. The belt conveyor or lifting winch is used as follows, and a four-quadrant inverter is selected. The power of the inverter shall be selected with reference to the rated current of the motor and greater than one level of the motor to meet the requirements for heavy-load starting. For the deep well pump (submersible pump) load, unlike the general pump load, due to the far distance from the inverter to the motor, it is necessary to increase the output sine wave filter to improve the output voltage and current waveform and increase the driving performance; When the frequency converter drives the water pump load, because the drain pump has a cubic characteristic load, that is, the higher the speed, the greater the resistance, so the start-up time of the inverter should not be too long, otherwise the pump will not be able to form a vacuum because it cannot be watered; The "water hammer effect" of the water pump, otherwise it will damage the pipeline and cause serious accidents. For fan load, when debugging, pay attention to the free rotation of the fan blades to cause the inverter to start over-current, so to increase the DC braking before startup, first make the blades stationary, and then start the motor.
2. Inverter's heat dissipation problem: For non-explosion-proof cabinets on the ground, pay attention to the matching position between the heat-generating components such as the reactor and the inverter, and try to avoid “circulating wind”, that is, the hot air of the reactor enters the inverter, which will affect the cooling effect. . For mining explosion-proof inverters, most of them use heat pipe cooling technology, and also use water-cooled heat dissipation technology. When designing cooling systems, they are mainly designed according to different power levels, while referring to the dissipated power parameters (including on-state losses) of the inverter module. And the switching loss is calculated, and there is a margin, and the heat dissipation effect has an important influence on the stable operation and life of the inverter. When using heat pipe cooling and cooling method, in the field use, should also pay attention to the installation and use of the environment, the inverter should be placed horizontally, is strictly prohibited "backward", otherwise affect the heat dissipation; also need to regularly clean the radiator surface dust, otherwise it will also affect heat radiation.
3. Leakage protection problem: The winch for mining uses the output voltage of the inverter as PWM wave, and the output current is close to the sine wave, but the input current wave is not a standard sine wave and contains high-order harmonics of considerable components. Therefore, the leakage protection system is used. Caused by malfunction or interference detection signal, so the conventional leakage detection can not be used in the inverter power supply circuit, should use a dedicated leakage protection device, but now the mine feed switch is the use of conventional leakage detection principle, the use of inverter After that, most of them caused power leakage jumps. Most of the current methods of processing are connected to high-voltage capacitors in parallel with the leakage protection detection circuit to eliminate high-order harmonic “glitches” in the detection signal; secondly, the leakage protection parameters can be optimized to reduce the leakage current according to the 30mAS (millisecond) principle. , Amplify the leakage protection time so that the product remains unchanged. In addition, the inverter jump feed power leakage protection, although related to the power characteristics of the inverter, but also with the feed switch is also related to different manufacturers feed switch protection setting is different, we must carefully study the instructions. Sometimes, there is a problem with the protection plug of the feed switch, which may cause the power supply to trip. At this time, the user often uses the inverter to talk about it. Therefore, it is necessary to carefully check, analyze the cause, and handle it properly. In the use of the inverter, it is important to pay attention to a good grounding, cross-section of the grounding line to meet the requirements, while the grounding electrode should be well grounded, grounding resistance is less than 3 ohms, these will play a certain effect to eliminate interference.
