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High-power portable energy storage power scheme introduction
- Jun 04, 2018 -

The portable energy storage power supply is a multifunctional portable AC/DC emergency mobile power supply device. It has a safe shifting lithium-ion battery and inverter conversion technology, and it is a “standby power station” with light weight, high capacity, and large power. Can provide you with convenient mobile power solutions, widely used in mobile office, medical rescue, fire emergency rescue, power equipment repair, environmental protection of the country, emergency communications security, and on-vehicle storage backup and other places

Technical features

1. Light weight, small size, easy to carry;

2. Can exchange 220V/110V output;

3 . LED emergency lighting, 24V/12V cigarette lighter output, 5V-USB output;

4. Using lithium-ion battery, safe and reliable environmental protection;

5. With LCD display

6. High-power PD and QC protocol TYPE-C output

7. Independent overvoltage, overtemperature, overload, overcharge, overdischarge, short circuit protection of the battery pack, automatic recovery

Function definition selection:

1. ACDC input charging power definition, efficiency requirements, whether wide voltage, whether it meets safety design requirements.

2. Battery capacity and serial connection method, as well as lithium protection circuit, and whether equalization technology is required

Lithium batteries (rechargeable) need protection because of its own characteristics. Since the material of the lithium battery itself determines that it cannot be overcharged, overdischarged, overcurrented, short circuited, and ultrahigh temperature charged and discharged, the lithium battery lithium battery assembly always follows a delicate protection board and a current fuse. Lithium battery protection function is usually coordinated by a protection circuit board and a current device such as a PTC. The protection board is composed of an electronic circuit and accurately monitors the voltage of the battery cell and charges and discharges the circuit at -40°C to +85°C. Current, timely control of the current circuit on and off; PTC in the high temperature environment to prevent the occurrence of bad battery damage.

Balanced charging is the charging method needed for all lithium batteries, but many low-power applications do not actually have balanced charging. For most laptop battery packs, the impact on battery life is considerable.

The existing equalization technology is mainly divided into energy balance between batteries and external energy input equalization. Energy balance between the batteries is to charge high-battery batteries to low-battery batteries. The biggest problem with this approach is that it is complicated to control.

Many dedicated chip or microcontroller solutions use an externally balanced approach, which is achieved through controllable energy consumption. In this approach, it is common to use an energy-consuming component to dissipate energy, waiting for other cells to fill or lower the voltage of some cells. The drawback of this solution lies in the fact that the power consumed by the zener diode is too high and the resulting heat generation is unbearable.

Another array of switches in balanced charging is implemented using power MOSFETs. This approach has high cost and complicated circuits. The tubes work in the on-off state and consume very little energy. In addition, the battery does not have series diodes to obtain maximum output. The disadvantage is that the circuit is more complicated, and the input charging circuit is required to be isolated because it needs to match the voltage of each battery.

3. Whether with LCD or digital display, display content: power, voltage, battery capacity, battery life, etc.

A fuel gauge chip is connected in series with the protection circuit of the battery, wherein an integrated resistor is connected in series, and the resistance value is generally between 20 and 30 milliohms. The basic principle is that a sampling resistor is integrated on the chip. When different currents flow through it, different voltage differentials are generated. The chip then integrates this voltage (actually converted into current) and time to get the correct amount of electricity when the user uses it. The unit of electricity is mAh). Many chips can achieve this function. TI's and MAXIM's several semiconductor chip companies all have similar products. After the battery is added to this chip, the cost is increased and the MCU is also asked for "communication". Then, after the chip obtains capacity through real-time integration, the data (in units of mAh) is stored in the EEPROM of the chip, and is transmitted to the MCU or DSP through the communication line according to the demand of the mobile phone. The exact capacity of this battery is obtained.

The coulomb meter chip, ie the memory of the metering chip, usually has the following basic battery information:

The initial capacity of the battery (mAh), which is the rated capacity, is the capacity obtained after a battery is fully charged.

Current battery capacity (mAh), battery capacity when in use.

The current (mA) flowing through it is the current consumption of the cell phone.

4. Whether or not inverter output is required and which method is used. Square wave inverter mode, modified wave inverter mode, pure sine wave inverter mode.

 The square wave inverter output is a square wave alternating current with poor quality, and its positive maximum to negative maximum value occurs almost simultaneously. This causes severe instability effects on the load and the inverter itself. At the same time, its load capacity is poor, only 40%-60% of the rated load, and it cannot carry inductive loads such as motors, washing machines, refrigerators, relays, and fluorescent lamps. If the load is too large, the third harmonic component contained in the square-wave current will increase the capacitive current flowing into the load. In severe cases, the load filter capacitor will be damaged. But the cost is low, more people use

   The output voltage waveform of the modified wave inverter mode has a significant improvement in the waveform of the modified wave compared with the square wave, and the higher harmonic content is also reduced. The traditional modified wave inverter is generated by step-by-step superposition of the opposite-wave voltage. This method has complicated control circuits. There are many power switch tubes used in the superposition circuit, and the volume and weight of the inverter are large. Many problems. In recent years, with the rapid development of power electronics technology, PWM pulse width modulation has been widely used to generate a correction wave output. Modified wave inverter method is suitable for the use of electricity quality requirements are not very high, with resistive electrical load

Pure sine wave inverter output is the same or even better sine wave AC power as the grid we use everyday. In conclusion, pure sine wave inverters provide high quality AC power, high efficiency, stable sine wave output, high frequency technology, small size, light weight, low interference to radios and communication equipment and precision equipment, and low noise. Strong load adaptability. It can drive any type of load (including inductive loads such as televisions, LCDs, and refrigerators) without interference (eg, noise and TV noise). However, technical requirements and costs are relatively high.

5. The DC output requires several sets of voltage and current. Whether or not it requires the TYPE-C output of the PD and QC protocols, and whether the voltage and current needs to be customized.

USB Type-C has the following features: The maximum data transmission speed reaches 10Gbit/s, which is also the standard of USB 3.1; The size of Type-C interface socket is about 8.3mm×2.5mm slim design; It supports both positive and negative sides. "Forward and reverse insertion" function, can withstand 10,000 times of repeated plugging and unplugging; Standard type connection cable equipped with Type-C connector can pass 3A current, while also supporting "USB PD" beyond the existing USB power supply capability, can provide the maximum 100W of electricity.

Currently, most of the PD and QC protocol chips on the market have good output voltage and current settings. Because the software is not open, the customized design requires high design capability of the company.