Solar inverter efficiency

Solar inverter efficiency
Solar inverter efficiency refers to as the demand for renewable energy, solar inverters (photovoltaic inverters) market is growing. These inverters require extremely high efficiency and reliability. These inverters used in Switch Power Supply circuits were investigated and recommended the best choice for the switch and rectifier parts. The general structure of the photovoltaic inverter shown in Figure 1, there are three different inverter available. Sunlight on the solar modules are connected in series through, each module contains a set of solar cells in series (Solar Cell) unit. Direct current (DC) voltage generated by the solar module in order of several hundred volts, the values according to the number of lighting conditions module array, and the temperature of the battery modules may be connected in series.
The primary function of this type of inverter is the input DC voltage is converted to a stable value. This function is achieved through the boost converter and the boost switch and boost diode needs. In the first configuration, after the boost stage is an isolated full-bridge converter. The role is to provide full-bridge transformer isolation. The second full-bridge converter output is used from the first full-bridge DC converter stage DC into alternating current (AC). Its output is connected to another network before being filtered through the AC power grid additional double contact relay switch

Components of the inverter

Components of the inverter
Component PV inverters are each connected to one inverter module, and each module has a single maximum peak power tracking, so that the components fit better with the inverter. Typically used for 50W to 400W photovoltaic online offline ups stations, the overall efficiency of less than string inverters. Because it is at the parallel exchange, which increases the complexity of the AC side of the connection, maintenance difficulties. Another need to solve is how to be more effective and power grid, the simplest way is to direct and network through an ordinary AC outlet, so that you can reduce installation costs and equipment, but often the safety standards of the country may not allow the grid To do so, the power companies are likely to oppose the power plant and the average home user is directly connected to an ordinary socket. Another relevant factor is whether you need to use and safety isolation transformer (high or low frequency), or allow the use of transformerless inverters. The inverter is the most widely used in glass curtain wall.

Centralized inverters

Centralized inverters
Centralized inverter system is generally used for large-scale photovoltaic power plants (> 10kW), the number of parallel PV strings are connected
To the same central inverter DC industrial ups power supply of the general three-phase IGBT power module, use less power field effect transistor, using DSP switch controller to improve the quality of the output power, making it very close to sinusoidal current. The maximum power of the system is characterized by high and low cost. But the influence of PV string matching and partial shading, resulting in efficiency and power capacity of the entire PV system. At the same time the entire photovoltaic power generation system reliability by poor working conditions of a photovoltaic cell groups affected. The latest research is the use of space vector modulation control, as well as the development of new inverter topology of connections to achieve high efficiency under partial load conditions. On SolarMax (Shohreh Mike) central inverter, you can attach an interface box PV array, photovoltaic panels on each string string monitoring, such as a string which is not working properly, the system will put the information passed to the remote controller, and can be stopped by a bunch of these remote control, so as not to because of the failure of a string of PV strings and impact of the work and reduce the energy output of the entire PV system

 

Fault Analysis and Maintenance（2）

Fault Analysis and Maintenance
Battery voltage is low, but start charging more than 10 hours of battery charge voltage is still not up.
Failure Analysis: Phenomenon judged from the battery or charging circuit failure, according to the following steps to check:
- Check the charging circuit input and output voltage is normal;
- If the charging circuit input is normal, the output is not normal, disconnect the battery
Then measured, if not normal, compared with the charging circuit fault;
- After disconnecting the battery charging circuit if the input and output are normal, then the battery is not charged due to long-term, over-discharge or other reasons, to the life of the damage.
 inverter online offline ups amplifier transistor pair is damaged, replace the same type of transistor, running for some time because they burn too much current, caused by excessive current reasons:
- Overcurrent failure. When the inverter output overcurrent, the overcurrent protection circuit does not work;
- Pulse Width Modulation (PWM) component failure, the two complementary output waveform asymmetry, a long lead-time, on-time and short the other, so that the work of unbalanced arms, even the arms are turned on simultaneously, resulting in two tube is damaged;
- Power difference between the larger tube parameters, then even if the input waveform symmetry, the output will be asymmetrical, the waveform is output transformer, causing magnetic bias, ie the flux imbalance, leading to the accumulation of down transformer saturation current surge, burn power tube, and a burn, the other also will burn.

Fault Analysis and Maintenance

Fault Analysis and Maintenance
When there is electricity high frequency online ups output is normal, no electricity when the buzzer sounding, no output.
Failure Analysis: From the phenomenon judged as part of the fault and reverse battery device, according to the following procedure to check:
- Check the battery voltage, to see whether the battery charging less, if the battery charging less, will have to check the battery itself is a fault or charging circuit.
- If the battery working voltage is normal, check the inverter drive circuit is working properly, if the driver circuit output is normal, indicating that the inverter is damaged.
- If the inverter drive circuit is not working properly, check the PWM control signal output waveform generator circuit or without, if the control signal output, indicating a fault in the inverter drive circuit.
- If no PWM waveform generation circuit control signal output, check its output is a result of the protection circuit and the blockade, if it is to identify the cause of protection;
- If the protection circuit does not work properly and the operating voltage, and waveform generation circuit without PWM waveform output then the waveform generator circuit damage.
Therefore, the discharge order can be reversed were sometimes able to quickly find faults.

Ups solar power input zero line of fire detection

Ups solar power input zero line of fire detection
To avoid UPS mains input zero FireWire reverse the machine with zero FireWire reverse detection.
· Bypass output humanity
To prevent users make three phase online ups work in BYPASS MODE not boot, causing electricity interruption, UPS and equipment are abnormal shutdown. ups mains input is normal, the default output without bypass. Must be turned on, will have a normal inverter output.
Input power factor correction
UPS with input power factor correction, under full load, the input power factor can reach above 0.99, so that the user's network environment is not contaminated.
· DC start
Under mains failure mode, if necessary use the UPS to start the computer or other loading equipment, UPS can boot directly to the battery current, making UPS more convenient and reliable.
· Bypass Protection
Bypass feature allows the UPS greatly enhance emergency response capabilities, while user load equipment for the power of special requirements, such as the voltage is not too high, UPS bypass supply voltage is too high protection, allowing users to load equipment from high voltage danger.
Automatic start function
When mains abnormal, enter the battery power mode until the end, UPS will shut down when the utility power is restored to normal, the United States and Europe and easy UPS will start automatically boot, normal power supply, one by one without user boot.
· Long-term power supply design
UPS offers a comprehensive long-term machine for users to choose. Configure the appropriate battery pack, allowing users to meet discharge requirements for the use of time in the case of different grid environments.

Ups solar power Work

Ups solar power  Work
In normal mains, electricity surge through absorption filter circuit → AC DC converter circuit to convert alternating current circuit → → DC and AC output converter supply the load and charge the battery at the same time; microprocessor control circuit to detect if electricity is interrupted is immediately discharged from the battery circuit → AC → DC converter and convert the AC supply output load. If UPS microprocessor control circuit detects a fault, then UPS will jump to borrow from the relay (RELAY) bypass (BYPASS), mains power supply load, and audible warning the user.
Performance
· Sine wave output
Whether in mains mode or battery mode, can be low-distortion sine wave output power for the user to load equipment for the best power protection.
· Zero transfer time
When power cut or re-power, UPS switch between AC mode and battery mode is no conversion time, effectively ensuring the reliability of the load operation.

Line sine wave output of the UPS has the following characteristics:

Line sine wave output of the UPS has the following characteristics:
(1) Due to on-line UPS, whether in the mains is normal, or power outages in the city by the machine during the inverter to the battery-powered, it loads are powered by the pure sine wave online ups inverter. Because of this, virtually eliminating the effect of any voltage fluctuations and interference from the mains to the load of work, truly non-intrusive regulator power to the load. This is obviously not any kind of interference AC power supply can be solved. When the voltage range of 180 ~ 250V city, its output voltage range up to 220V ± 3%, stable operating frequency range of the sine wave at 50Hz ± 1%.
(2) the waveform distortion coefficient line UPS output sine wave of the minimum, generally less than 3%.
(3) mains interruption can realize on-line UPS uninterruptible power supply to the load. As long as the machine battery can provide power to the UPS inverter, whether electricity is interrupted, on-line UPS is powered by the inverter to the load. Therefore, the power supply from the mains to the mains interrupt the process, on-line UPS internal action did not produce any conversion, the conversion time is zero power to the load.
(4) On-line UPS with backup UPS, compared with excellent output voltage transient characteristics. Generally l00% or 100% load load load load shedding, its output voltage range of about 1%, the change of duration is generally from 1 to 3 cycles.
(5) On-line UPS generally used above 20kHz PWM technology, the smaller the noise, about 50dB.
(6) on-line UPS control circuit, using the input transformer, the output transformer and a photocoupler device like "ferroelectric" driving part and "weak" control line portion isolated from the electrical point of view, and thus the reliability of the circuit is greatly improved. This UPS failure rate is generally low.

When the on-line UPS power supply in normal

When the industrial ups power supply power supply in normal, power input voltage noise filter removes all the way through the grid frequency interference in order to obtain pure AC rectified and filtered into the rectifier and converts AC power to DC smoothing, then divide for two-way, all the way into the charger for charging the battery, the other way supply inverter, and inverter turn DC into AC 220V, 50Hz supply load.
When utility power outage occurs, AC input has been cut off, the rectifier is no longer working, then the battery discharge the energy delivered to the inverter, and then by the inverter converts DC into AC for load. Therefore, the load, despite the utility has ceased to exist, but this time the load is not interrupted due to electricity outage, you can still operate normally.

Is the battery (maintenance-free lead-acid batteries, mostly)

Is the battery (maintenance-free lead-acid batteries, mostly) and the host is connected to the host via an inverter module converts the DC circuit mains system equipment
Power supply is mainly used for a single computer, computer network systems, or other power electronic devices such as solenoid valves, pressure transmitters provide a stable, uninterrupted
Online means regardless of the grid voltage is normal, the load to go through with the AC voltage inverter circuit, inverter circuit that is always active, on-line double conversion UPS generally structure. The so-called double-conversion computer ups power supply refers to normal working hours, power through the AC / DC, DC / AC conversion twice and then supplied to the load.
This UPS uninterruptible power supply so that the inverter has been in working condition, it is first converted by circuitry external AC to DC, and then through the high quality of the inverter to convert DC into high quality sine wave AC output to the computer. Online UPS power supply situation in the main function is regulated and prevent radio interference, while the battery charge management; backup during power outages using a DC power source (battery) power to the inverter. Since the inverter has been at work, so there is no problem switching time for the power supply, there are strict requirements of the occasion.

The inverter three phase online ups stage one pair amplifier transistor

The inverter three phase online ups stage one pair amplifier transistor is damaged, replace the same type of transistor after running for some time because they burn too much current, caused by excessive current reasons:
- Overcurrent failure. When the inverter output overcurrent, the overcurrent protection circuit does not work;
- Pulse Width Modulation (PWM) component failure, the two complementary output waveform asymmetry, a long lead-time, on-time and short the other, so that the work of unbalanced arms, even the arms are turned on simultaneously, resulting in two tube is damaged;
- Power difference between the larger tube parameters, then even if the input waveform symmetry, the output will be asymmetrical, the waveform is output transformer, causing magnetic bias, ie the flux imbalance, leading to the accumulation of down transformer saturation current surge, burn power tube, and a burn, the other also will burn.

 

In normal mains

In normal mains, electricity surge through absorption filter circuit → AC switch DC circuit AC circuit → → DC converter and convert the AC output supply load, and at the same time charging the battery; Once microprocessor control circuit detected mains interruption, → immediately convert DC three phase online ups discharge and converts alternating current circuit → AC output supply load. If UPS microprocessor control circuit detects a fault, then UPS will jump to borrow from the relay (RELAY) bypass (BYPASS), mains power supply load, and audible warning the user.

 

When the mains input is normal

When the mains input is normal, UPS will supply the electricity regulator to the load, in which case the online offline ups is an alternating electric regulator, while also charging the energy storage device such as a battery pack; When the mains interruption (accident blackout) when, UPS immediately energy storage device (such as a battery or flywheel energy storage system) through an inverter to convert alternating current to the load supply methods continue to make to maintain the normal work load and protect the load software and hardware from damage . UPS devices usually low voltage and voltage are too large to provide protection.