MSpowerboost Inverter Low Voltage Ride-Through Cabinet

Product Overview

The MSpower series low-voltage ride-through device, as one of the motor safety power sources, is widely used in industries such as petrochemicals, steel, and smart manufacturing. Continuous production enterprises are affected by grid fluctuations, which can cause voltage disturbances and sags. Voltage disturbances often originate from the upper-level power distribution, posing risks of sudden shutdowns for motors and frequency converters.

The concept of low-voltage ride-through originated from wind farms, aiming to ensure normal power generation and grid connection during system faults and voltage drops, thereby reducing grid fluctuations. It has now been extended to various sensitive critical loads. These loads are started via frequency converters, and when grid disturbances occur, the frequency converters face shutdown risks, jeopardizing process continuity. The MSpower Boost series low-voltage ride-through cabinet, through seamless integration with frequency converters, ensures continuous and safe motor operation during transient grid disturbances and short-term power outages.

The MSpower Boost series low-voltage ride-through device, as a new-generation anti-flicker device for frequency converters, offers more comprehensive advantages compared to conventional motor safety power sources. By comprehensively measuring the input and output of frequency converters and intelligently identifying operating conditions, it employs system bus technology to monitor the rectifier module, Boost module, DC bus voltage, and frequency converter bus voltage in real time. The low-voltage ride-through cabinet uses an industrial touchscreen for real-time dynamic display of operating conditions. It features equal power configuration with the motor to reduce redundancy waste; supports isolated multi-channel output to lower system costs; has a simple and effective structure without adding failure points; and offers advantages such as low power consumption and zero-delay bypass activation.

Product Features

☆ The low-voltage ride-through device adopts a fully enclosed cabinet with strict separation of strong and weak currents, ensuring strong anti-interference capability.

☆ Seamless integration with frequency converters, offering excellent compatibility.

☆ Bypass operation mode, without increasing the original system risk.

☆ Dynamic tracking of bus status with zero activation delay.

☆ One device can drive multiple frequency converters without circulating currents between them.

☆ Comprehensive device testing functions for convenient on-site debugging and inspection.

☆ Redundant system design for reliability and stability.

☆ Holographic system recording and full lifecycle prediction.

☆ Multiple self-check methods for key components to ensure long-term stability and reliability.

☆ Intelligent air-cooling system and active heating and dehumidification system to ensure optimal operating conditions.

Equipment and Function Configuration

The MSpower Boost series low-voltage ride-through device is a critical safety power source for frequency converter-controlled motors. As an energy-saving and safe flicker-proof cabinet, it is applied in various frequency conversion circuits of small, medium, and large power capacities. Based on the distribution of on-site control systems and ride-through duration, it can be categorized into the following models:

MSpower Boost Standard Type

The standard MSpower Boost series low-voltage ride-through device supports one frequency converter per unit without external DC power input. It is suitable for frequency converters below 10KW operating in relatively stable power supply environments. This standard type can be customized to support two frequency converters per unit, with each frequency converter not exceeding 5KW.

MSpower Boost Backup Type

The backup MSpower Boost series low-voltage ride-through device is suitable for environments with poor power supply conditions, occasional power outages, or situations where high-voltage side switching operations result in prolonged power outages. By adding an extra backup DC system to the standard type, it enables longer ride-through durations. A typical configuration supports five minutes of backup operation. If the system requires longer ride-through durations, the MSpower Battery series products should be selected to support approximately 30 minutes of system operation.

System Overview

The MSpower Boost series low-voltage ride-through device achieves ride-through functionality via a bypass frequency converter. Its input is three-phase AC power, and its output is DC power. When a voltage sag occurs, it quickly activates a stable DC power supply to maintain normal operation of the frequency converter. The schematic diagram of the device structure is as follows:

Figure 1: Schematic Diagram of Device Structure

Three-phase AC power enters the three-phase rectification circuit through circuit breaker QF1. Pulsating DC is pre-charged to capacitor C1 via current-limiting resistors. After pre-charging, the current-limiting resistors are bypassed by DC contactor KM1 to fully charge capacitor C1. Inductor L1, along with Q1 and Q2, forms a Boost-type step-up circuit, pumping the DC charge from C1 to a higher voltage to charge capacitor C2. Capacitor C3 is charged via pre-charging current-limiting resistors, and the power is delivered to the frequency converter's DC bus through thyristors, diodes for reverse current protection, DC contactors, circuit breakers, and fuses.

Under normal operating voltage, the frequency converter maintains operation through its internal bridge rectifier DC power supply, while the Boost step-up circuit remains on standby. When the grid voltage experiences an instantaneous drop and reaches the set value (default 80%, adjustable), the Boost circuit quickly activates, outputting a stable DC voltage to support the frequency converter's DC bus voltage, thereby maintaining the speed and torque of the frequency-controlled motor. Once the grid voltage recovers (default 90%, adjustable), the Boost step-up circuit automatically deactivates, and the frequency converter resumes operation via internal rectification.

This low-voltage ride-through device operates in bypass mode. The original AC power supply line of the frequency converter requires no adjustment, and no new settings are needed for the frequency converter. It can be installed locally next to the original frequency control cabinet. If the original control cabinet lacks a stable DC or uninterruptible power supply, the original control holding circuit will trip during voltage sags. In such cases, an uninterruptible power supply must be added during project modification to maintain the original control circuit.

Device Appearance Description

Due to varying power capacities, cabinet dimensions may differ significantly. Pre-orders are accepted!