Huabao Golden Warrior UPS Power 2020-06-18

With the continuous development of automation and informatization, various industries have more and more demand for power and higher and higher requirements for power protection. UPS power supply, as an important equipment to ensure the stability and continuity of power supply, has been widely used in various fields. UPS power supply has developed to the present, and there are various models on the market. Among them, industrial frequency machines, high frequency machines, and modular models are the three most common models in the UPS power supply market. This article starts from the basic principles and applications. Features introduce these 3 models, and compare various indicators for reference for user selection.

Before talking about the high-frequency machine of the power frequency machine, we first clarify the definition of the high-frequency machine and the power frequency machine. There is no such thing as a high-frequency machine and a power frequency machine in foreign countries. They define transformer-type and transformer-less UPS, namely TransformerUPS and Transformer-lessUPS. Domestically, it is distinguished by the modulation frequency of the rectifier. The modulation frequency of the rectifier is a power frequency (50Hz) modulation, which is defined as a power frequency machine, and the rectifier uses a high frequency (thousands of Hz) modulation, which is defined as a high frequency machine.

In addition, there are RacktypeUPS, ModularUPS and TowertypeUPS models to distinguish UPS from the appearance structure. This is relatively easy to understand, and the UPS that is easy to install in a standard server or network cabinet is called a rack-mounted UPS. A model composed of a modular structure for power units and bypass switching units is called a modular UPS. The overall model designed according to the specified power is called the tower model. Generally speaking, high-frequency and industrial frequency machines refer to tower models. Rack-mounted UPS just adjusts the physical structure of low-power (less than 20KVA) tower models to suit rack installation. This article does not apply to rack-mounted UPSs. Conduct comparative analysis.

1. Power frequency machine

The power frequency UPS is the UPS power supply based on the output of the transformer. It uses SCR thyristor devices as the rectifier components. The modulated operating frequency of the rectifier is consistent with the grid frequency (50Hz). This type of model is called a power frequency machine. The power frequency UPS is composed of rectifier, inverter, static bypass, maintenance bypass, and output transformer. The output transformer is a necessary part of the UPS power supply and plays a role in boosting. Because the two conversions of UPS rectification and inverter are step-down links (SCR tube voltage drop), there must be a step for step-up before UPS output. This output transformer is used to achieve this function.

There are two types of common power frequency machines, 6-pulse power frequency rectification and 12-pulse power frequency rectification.

The 12-pulse rectifier power frequency machine adds a 6-pulse rectifier and a phase-shifting transformer on the basis of the 6-pulse, which can bring better rectification parameters. Compared with the 6-pulse rectification, the 12-pulse rectification is in the input Power factor and harmonic current THDi parameters have obvious advantages.

At present, industrial frequency machines are gradually shrinking in the market, especially in data centers and communication rooms, which have been gradually replaced by high frequency machines and modular UPS. Power frequency machines also have their own characteristics. In the industrial field, especially in the petroleum and petrochemical, chemical, and high-end manufacturing industries, power frequency machines are still the protagonist. In the entire UPS power supply industry, the market share of power frequency machines remains above 30%.

2. High frequency machine

There are three common types of high-frequency machines. In the late 1990s, a BOOST step-up chopper circuit was added to the back of the SCR rectifier to boost the DC to the voltage required by the UPS output, thereby eliminating the need for an output transformer. It can be simply understood as replacing the AC boost of the previous industrial frequency UPS transformer with DC boost, which not only lowers the cost, but also greatly reduces the volume and weight of the UPS. It can be said to be a major technological innovation in the UPS industry. This kind of transformerless UPS, although the first half of the rectifier is still an SCR device, the second half of the rectifier contains an IGBT high-frequency step-up chopper circuit, which is also a high-frequency machine from the domestic definition. At present, this kind of BOOST step-up chopper high-frequency models has become less and less, and only some medium and small power UPS will continue to use.

With the continuous development of power electronic power devices and UPS power control technology, all IGBT models and all IGBT + output isolation transformer models have appeared successively, namely IGBT rectifier + IGBT inverter without transformer and IGBT rectifier + IGBT inverter with transformer Model, its rectifier adopts high frequency adjustment method, and the modulation frequency is generally thousands of Hz.

The biggest feature of high frequency machine is no transformer, small size, light weight, high power density, high efficiency of the whole machine, and low input harmonic current. Therefore, its development prospects are even more promising. High frequency is the development trend of power electronics. However, from the perspective of application, the high-frequency machine is still inferior to the more mature industrial frequency machine in terms of environmental adaptability and impact resistance.

With the increasing demand for green power supplies and energy-saving and consumption-reducing products in the social power supply environment, the high-frequency IGBT rectifier UPS power supply technology has been greatly developed, and the reliability and stability of IGBT devices have also been greatly developed. More and more users choose high-frequency machines, especially in the field of data center, finance, and communications. High-frequency machines have become the first choice for users.

Three, modular models

Modular UPS is to make the power part of the high-frequency UPS separately into power modules, and then each module is output in parallel. In addition, the bypass switching module and the control unit are also made into modular units, so that the entire UPS is a stack of modules. to make. The biggest feature of modular UPS is that the power part can easily realize the redundancy function. As long as the UPS load power margin is greater than the power of a single module, the UPS power part can achieve "N+1" redundancy, thereby improving the reliability of UPS power supply . Another advantage of modular UPS power supply is its high availability. When a module fails, the module can be replaced directly. The maintenance time is very short and the maintenance is very convenient. In addition, modular UPS often mentions the "investment while growing" model, that is, users can purchase fewer power modules during initial construction, and then purchase power modules for UPS expansion after business growth increases in user equipment.

Soon after the appearance of high-frequency machines, modular UPS came into being. In theory, modular UPS is also a kind of high-frequency machine, but its structure is quite different from ordinary high-frequency tower models. Modular UPS has relatively high requirements for parallel control technology. Early modular UPS has a high failure rate, and the cost of each maintenance and replacement module is not low. Therefore, there are few users who choose modular UPS power supply, which is not the mainstream of the market. However, with the gradual maturity of parallel control technology, the reliability of modular UPS has gradually improved, and its high efficiency and high availability characteristics have gradually been recognized by the market. In particular, Huawei has reproduced the UPS market with modular UPS, and rapidly promoted the rapid development of modular UPS , Its market share has risen sharply, especially in the IDC information room, finance and other fields, and it has been on par with high-frequency tower machines.