Multi-stage injection current source inverter

The concept of harmonics injected power converters have been used in the history of half a century . But the harmonic injection for power converter as a way to reduce the harmonic content . Multi-stage injection current amplitude and phase matching conditions of work , through the use of additional thyristor trigger control and achieve a natural commutation ripple voltage , frequency and phase of the injected current synchronized with the power supply . Based on the fixed relationship between the amplitude of the injected current and direct current , the optimal harmonic suppression is guaranteed for all operating conditions , the DC voltage waveform and the alternating current waveform quality is further improved. In the literature , the concept of a new injection of DC current , and found six times the fundamental frequency of the injected current with the pulse current source converter 12 can play full effect of suppressing harmonics . Which research methods to find unconventional system of injection current waveform amplitude , so as to achieve a minimum harmonic distortion rate . And rigorous mathematical analysis summarized this idea , the ability to completely eliminate export standard 12-pulse current source  2000 watt power inverter   AC output waveform measured ideal harmonic injection waveform. 12-pulse current source converter , the operating mode of the main circuit and the general three-phase full-controlled bridge converter same , each bridge in six 60 ° intervals sequentially triggered thyristor conduction, each main switch is turned on 120 bridge °. Thus, for two parallel three-phase full -controlled bridge , the bridge every 30 ° to trigger a switch arm , any time there are two switch conduction. It does not change with the AC system voltage , system synchronization and communication connections can also be run as a rectifier and an inverter operation . When the active power fed from the AC system to the DC system , the state of the rectifying operation of the apparatus , when the conveying system to the alternating current from the active system , the device in the inverter state . Multi-stage injection current source  Off grid inverter  (MLCR-CSC) DC voltage can be positive or negative, the converter requires the use of a switching device with symmetrical features , namely bi-directional voltage blocking capability and unidirectional current flow capacity of the device has . So IGBT can not be directly used for MLCR-CSC, diode and IGBT series to meet this performance requirement , but the device will cause a series of additional power loss. Since MLCR-CSC relatively low switching frequency, suitable for high-power thyristors MLCR-CSC. Due to the presence of DC side inductance , making DC current flow in one direction , while the DC voltage polarity may change instantaneously , so the multi-stage injection current source inverter switching devices need to be bi-directional voltage blocking capability and unidirectional current flow capacity .

Impact crusher Precautions

1, regular observation opens the door to observe the impact of downtime Sand internal wear, center feed tube , cone hat, the impeller , indecent Road liner , circular shield , the degree of wear wearable pieces of worn should be replaced or repair, replacement should be replaced at the same time wearable pieces , wearable pieces to ensure the same weight . Crusherm ppt solar controllers  work process open the door to observe the inner workings of observation is strictly prohibited , to avoid danger. Timely replacement of worn impeller body found find manufacturers repair. Special attention , without the consent of the manufacturer is prohibited without permission homemade impeller.

2 , Sand to 400 hours of work time should be added the right amount of grease to work until 2000 hours when necessary to open the Order of the spindle assembly for cleaning , and must be replaced if the time to work after 7200 hours bearing it.

3 , the drive belt tensioning Triangle car inverters  appropriate size should be adjusted to ensure that the tape should be grouped matching triangle , then its length as consistent as possible in each group . They should be adjusted to the difference between the two motor current does not exceed 15A.

4 , during operation , due to the high speed devices belonging Sand , particular attention should be safe . The staff should stay away from the device , then the For machine repairs must only be carried out after a power failure .

True and noise waveform off the degree of photovoltaic power systems and networking -type photovoltaic power generation system inverter control function is also very major skills .

( 1 ) should have enough additional output capacity and load order . Inverter selection, from the primary thinking has enough extra capacity to meet peak load requirements of electric power equipment . Load on a single device for the inverter , the extra capacity extractor relatively simple, when electrical equipment is purely resistive load orDC AC power inverters power factor greater than 0.9, the extractor additional ca pacity inverter power equipment capacity from 1.1 to 1.15 times can be. To multiple devices in the inverter when the load capacity of the inverter to disconnect the electrical equipment is also thinking about a few tasks Off grid inverters  can , ie \ load also factor \ .
( 2 ) should have a higher voltage constant function. In the off-grid PV systems are battery energy storage devices. When the nominal voltage of 12V battery in the form of a floating charge , terminal voltage up to 13.5V, the short time overcharge shape up 15V. When the battery terminal voltage with load discharge end can be reduced to 10.5V or less. The terminal voltage of the battery is about 30% of nominal voltage up to the rugged

The principle of solar inverters

Usually convert ac power to dc can call rectification, the process of phase controlled rectifier is one of the most common ac to dc conversion process; And call direct current process which can transform into ac power inverter, it is the inverse process of rectification. In the inverter circuit, according to the properties of the load, inverter can be divided into active and passive inverter inverter. If the ac side of the circuit to the ac power, convert direct current (dc) can pass straight - communication, inverter to the ac power up with frequency alternating current (ac) to return to the grid, called active inverter. The corresponding device is called active inverter, control Angle is greater than 90 ° phase rectifier for common active inverter. And direct current (dc) can transform into ac power, directly to the power supply circuit, power supply load is called passive inverter circuit, also known as the frequency converter.
Inverter type has separately excited, self-excitation inverter,  2000 watt power inverter  pulse width modulation (PWM) inverter. Which he excitation voltage source inverter need external communication, provide thyristor rectifier voltage. He wound inverter is mainly used in high power grid; Whose power is less than 1 mw photovoltaic power generation systems, mainly adopts the way of self-excitation inverter. Self-excited does not require an external voltage source inverter, rectifier voltage by the  2500 watt power inverter  part of the energy storage element (such as capacitance) to provide or by increasing stay shut off rectifier valve (like MOSFET and IGBT) resistance value. Be self-excited pulse modulation inverter output voltage is called the pulse inverter. This kind of inverter pulse switching times, by increasing the cycle to reduce the harmonic content of voltage and current; Harmonic content was positively than with pulse switching times. At present, the output of the grid inverter control mode there are two main types: voltage type control mode and current mode control mode. Voltage type control mode based on the principle of the output voltage controlled quantity, as the system output voltage and power grid of the same frequency and phase of voltage signal, the whole system is equivalent to a controlled voltage source internal resistance is small; The principle of current mode control mode is output inductor current as control target, the system output voltage and power grid of the same frequency and phase current signal, the whole system is equivalent to a larger internal resistance of the controlled current source.
At present, there are many kinds of solar inverters, topology structure, the most common of which are used for single-phase half bridge, bridge and HerIC (Sunways patent) inverter, as well as six pulse for the three-phase bridge and midpoint clamping (NPC) inverter. Solar inverter four commonly used the typical architecture of full bridge topology of the switch

Frequency inverter maintenance Cautions

1) UPS should be noted that the use of a well-ventilated environment, conducive to heat and keep the environment clean.
2) Do with  6000 watt power inverters  loads, such as cash registers, fluorescent lights, air conditioning, etc., to avoid damage.
3) UPS output load control in about 60% for the best, highest reliability.
4) UPS load is too light (eg 1000VA, 100VA UPS with load) may cause deep discharge of the battery will reduce the battery life, should be avoided.
5) appropriate discharge, helps cell activation, such as long-term non-stop electricity, every  2500 watt power inverter  months to be artificially broken mains load discharge time with UPS tape, so you can extend the battery life.
6) For most small UPS, go to work and then open the UPS, to avoid load at boot time to start, should work to close UPS; For network room UPS, because the majority of the network is 24 hours, so the UPS must run around the clock.
7) UPS should be charged after discharge to prevent battery damage due to excessive self-discharge.