Theory of Operation

2.2.4Inverter

The inverter is a solid state device that converts the DC output of the rectifier/charger or the battery to AC power.

Operation

The inverter converts DC power—from either the battery or the rectifier/charger—into three pulse- width-modulated/six-step waveforms. These waveforms are filtered into low-distortion sine wave power. The inverter is controlled by digitally controlled logic. This logic controls the precise synchro- nization, amplitude and frequency of the output voltage.

In addition to the inverter efficiently supplying a regulated AC output from a DC source, the output isolation transformer acts as a second stage of isolation between the critical load bus and the commer- cial source power. The inverter is configured to handle most critical load inrush surges. It maintains output voltage Total Harmonic Distortion (THD) within specifications even when handling non-linear computer loads. Refer to Non-Linear Load Characteristics.

Output Regulation and Overload Performance

The inverter is capable of sustaining full output voltage (±2% of the nominal voltage) for up to 150% overload at the output for as long as 30 seconds without reducing the output voltage. It can also han- dle at least 125% of the rated current for up to 10 minutes and 104% of the rated current continu- ously. The System Control Cabinet (SCC) will transfer the critical load to the bypass source if the overload exceeds the system capacity or the capacity of the modules on-line. The multi-module over- load capacity (in terms of percent of rated full load current of modules on-line) is 140% for 20 seconds, 108% for 10 minutes and 104% continuously.

Note that in normal operation the SCC will transfer the load to bypass before a UPS module exceeds its overload capacity. If an individual module overload condition is sustained (beyond inverter capac- ity) the UPS module is automatically taken off-line (disconnected from the critical bus) and is shut down. If the UPS system is operating in the redundant mode, the load may remain on the UPS sys- tem. Refer to 3.5 - Automatic Operations.

Non-Linear Load Characteristics

Computers and computer equipment with switching power supplies generate non-linear currents rich in fifth and seventh harmonics.

The inverter pulse-width-modulated/six-step waveform, coupled with the output filter, provides a nat- ural path for reducing the fifth and seventh harmonic currents produced by the load. The inverter/fil- ter limits the output voltage THD to less than 5% with up to 100% typical electronic data processing (EDP) loads. EDP equipment characteristically includes both non-linear and linear load components.

Unbalanced Load Characteristics

Unbalanced loads are actively regulated. The phase-to-phase voltage balance is maintained to within 2%, even with a 50% load imbalance.

The three-phase, root mean square (RMS—approximately 70% of the peak) average voltage is also regulated through a separate control circuit (phase-to-phase sensing).

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Emerson Series 610 manual Inverter, Output Regulation and Overload Performance, Non-Linear Load Characteristics
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Series 610 specifications

The Emerson Series 610 is a cutting-edge solution for precise process measurement and control, designed specifically for industries where accuracy and reliability are paramount. This advanced instrument, often utilized in oil and gas, chemical processing, and water treatment sectors, combines innovative technology with robust features to meet the demanding requirements of modern industrial applications.

One of the standout features of the Series 610 is its exceptional measurement accuracy. The device employs advanced sensor technology that enables precise determination of variables such as pressure, temperature, and flow. This accuracy translates into improved process efficiency and enhanced product quality. With a wide range of measurement capabilities, the Series 610 can handle varying process conditions and fluid types, making it versatile across different applications.

The heart of the Emerson Series 610 lies in its intelligent diagnostics and predictive maintenance functionalities. This built-in technology allows for real-time monitoring of the device's operational status, providing valuable insights into performance trends. By detecting anomalies early, users can take proactive measures to prevent potential failures, thereby reducing downtime and maintenance costs.

Moreover, the Series 610 is designed with user-friendly features. Its intuitive interface and easy-to-navigate menus facilitate quick setup and configuration, enabling operators to be productive from the outset. The device also supports various communication protocols, including HART and FOUNDATION fieldbus, ensuring seamless integration into existing control systems and enhancing overall automation capabilities.

Another notable characteristic of the Emerson Series 610 is its robust construction. Designed to withstand harsh environmental conditions, it is built with durable materials that offer high resistance to corrosion and physical damage. This durability ensures longevity and reliability, even in the most challenging industrial environments.

In summary, the Emerson Series 610 represents a significant advancement in process measurement technology. With its exceptional accuracy, intelligent diagnostics, user-friendly design, and robust construction, it is an ideal choice for industries seeking to enhance their operational efficiency and reliability. Its ability to seamlessly integrate into existing systems further solidifies its position as a leading solution in the field of industrial measurement and control. As industries continue to evolve, the Series 610 is poised to meet the challenges of the future with confidence and precision.
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