I. Product introduction
This system is the intelligent power supply product with independent intellectual property right developed on the latest U.S. microcontroller (MCU) simulation platform for two years, this product adopts digital phase synchronization lock technology, the system can realize totally independent current equalization, the online hot plug can increase or reduce the parallel module and realize (N+X) hot plug parallel redundancy. When some module has failure, the failure module will be withdrawn immediately and alarm, the rest modules will automatically equalize the load, and the system will continue the normal operation. The inside system adopts standard industrial bus: CAN (Controller Area Network) bus, with high stability and anti-jamming. Products of all technical indicators are met or exceeded the national standards developed by the Ministry of Information Industry. Can be widely applied to communications, electric power, railway, national defense, such as solar power uninterruptible power supplies for high reliability requirements of the occasion.
II. Main characteristics
2.1 Advanced control technology
Real non master-slave, independent
Adopt multi-homed, open field industrial bus-CAN bus to realize system parallel operation.
Adopt the latest U.S. high-performance industrial built-in MCU control.
Digital phase synchronization lock control
Output current equalization control with fast response speed (<2%).
Adopt 100K HZ high frequency design.
The module has no address code and can be combined freely.
2.2 Highly reliable, flexible power supply configuration
Maximum parallel modules: 20 (theoretically infinite)
Module power degree: 2K, 3K.
2.3 Reliable protection function
Multiple protection function with combination of software and hardware.
Static bypass unit module, totally realize continuous switching.
Input to ground, output to ground, input to output are totally isolated.
2.4 Good electromagnetic compatibility design
Good reflected noise index, far less than the national allowable range.
Ultra low radiation interference, comply with FCC Class A standard.
2.5 High-quality component
The main components adopt international brand.
2.6 Good structure design
Due to advanced control technology and good structure design, the equipment is small and light.
2.7 High overloading capacity
10min for 125% overload; 150 overload, 150%.
2.8 Intelligent fan
The fan will be inched if the internal temperature is below 30℃.
The fan will make intelligent speed regulation if the internal temperature is 30℃～60℃.
The fan will run in full speed if the internal temperature is 60℃～90℃.
The equipment will be automatically off for protection if the internal temperature is above 90℃.
2.9 Maintenance-free design
(N+X) real no master-slave, independent current equalization parallel redundancy.
Online hot swap.
2.10 Multilayer monitoring function
Large-size TFT true color LCD monitoring module, the working condition of the system and each module is obvious, the failure alarm information is provided, all in Chinese display. With RS-422 interface, can realize centralized monitoring.
256 alarm records
2.11 Precise, reliable output power supply switching
The static bypass module panel with standard switching button can freely set and continuously switch between inverter load and commercial power load.

III. System composition
This system is composed of redundant parallel inverter module, static bypass module, monitoring module, rack (including distribution unit), where:
1) The inverter module can be directly paralleled for independent work;
2) The static bypass module, monitoring module and distribution unit are optional parts.

IV. System module introduction
4.1 Parallel inverter module
The standard parallel inverter module power is: 3KVA.
The appearance dimensions for the models of DC48V, 110V, 220V input are the same (2U height).
The equipment adopts non master-slave, independent current equalization type digital phase synchronization lock technology, which increase or reduce the parallel module and realize (N+X) hot plug parallel redundancy without disconnecting the load. When some module has failure, the failure module will be withdrawn immediately and alarm. The standard use of this equipment is multi-module parallel use, and the equipment can also be used in single machine.
Working principle
The voltage provided by DC power supply is increased to the high frequency step-up part through fuse, relay, filter, boosts 48V DC into 720V DC to meet the working requirement of inverter power devices. The high-frequency inverter part will transform 720V DC into 220V, 50HZ AC, and send to the output end through the relay after being filtered. The controller controls the on/off of input and output relay, (when the internal or peripheral device of the equipment fails, the relay will be disconnected, it will be closed in normal condition) and regulates and controls the working status and output of high-frequency step-up and high-frequency inverter at the same time. The filter filters out the high frequency component inside the equipment, and isolates them from the input end and output end without affecting other connected peripheral equipment.
4.2 Static bypass module
The static bypass module has three power degrees: 15KVA, 30KVA, 60KVA, with the respective matched full system power of 15KVA, 30KVA, 60KVA.
The chassis dimensions of the static bypass modules with 3 power degrees are the same, 3U height.
Working principle
The static bypass unit is used to choose the output switching of commercial power supply/inverter power supply system.
There are two operating modes to choose: 1. the inverter power supply system for the online operation, and the commercial power supply is standby; 2. the AC commercial power supply for operating power supply, the inverter powers supply for short (less than 10 minutes) standby. The inverter power supply will track/lock in the phase frequency of commercial power supply in both working modes, and will be switched to the standby power supply if the power supply in the operation fails. Due to the adoption of fast tracking/switching static bypass switch controlled by microprocessor, this system will not reset the computer system during the bypass switching period.
The zero line outputted by this inverter system, with the commercial power supply zero line is connected to the loaded zero line, the live wire is respectively switched to the loaded live wire through large power two-way silicon control JK1, JK2.
When the system is electrified, the control unit respectively detect the phase outputted by commercial power supply and inverter system, and send tracking command to each module through system bus (CAN bus), the system will be automatically locked and complete the phase synchronization lock when the phase difference is less than 1.5 °, the whole process will last for decades of milliseconds. Then the inverter system will accurately keep phase synchronization lock with the commercial power supply.
4.3 Monitoring unit
Principle
The monitoring unit adopts 6inch TFT true color LCD.
The monitoring module is composed of data collection, data processing and LCD and its drive.
Data collection samples the input DC voltage and output AC voltage, collects the total input current on DC bus through Hall sensor installed on the distribution unit at the same time, and sends to data processing together with the operating parameters as working status, output current from each module; send the data to the data display part through internal bus. The data display part is composed of TFT color LCD and its drive circuit, its function is to respectively store/display various current, voltage data and failure alarm information from each inverter power supply module, different display pages can be chosen through pressing the page button on the panel.
Data display part is composed of TFT color LCD and its drive circuit, its function is to respectively store/display various current, voltage data and failure alarm information from each inverter power supply module, different display pages can be chosen through pressing the page button on the panel. One minute screen saver can be set, the display will be automatically off if no operation is made within one minute, press the page button for consulting any information.
Data communication component processes various voltage, current and failure alarm information, failure records (256 records) of the system through RS_422 or through TCP / IP protocol stack, send to the computer through the serial port or package into standard data frames compatible with Internet, send to the remote monitoring computer platform through LAN or Internet, and realize remote monitoring.
The inside of the system swaps various monitoring information through CAN (Controller Area Network) bus, therefore, the system is a micro-network system that complies with CAN protocol and has various monitoring contacts.
4.4 Distribution unit
Power distribution unit is installed in the upper rack, which is available after a small upper door installed with display. The distribution switch is composed of input DC power switch, AC output branch switch, to respectively control DC input and system AC output branches of the inverter system module. AC output can be directly connected into the field distribution box through system output bus (Lso), or directly multiple output with load from the AC output branch.
There is an “Auto/Manual” switch for bypass repair purpose on the distribution panel. It’s used to swap the load to the commercial power supply after switching the static bypass into BYPASS terminal, so as to repair the static bypass unit.

V. Technical index
5.1 Performance index