Introduction:
Our company's modular frequency converter adopts an active PFC thyristor rectifier+high-frequency isolated bidirectional DC/DC converter+high-frequency three-phase or single-phase sine inverter circuit topology, omitting the output power frequency isolation transformer that has the greatest impact on the volume and weight of the variable frequency converter. Under the same output power capacity, our modular frequency converter is one-third of the current volume and one-quarter of the weight of tower frequency converters.
Our modular frequency converter adopts standard 19 inch 2U modular chassis structure. Each power module has the same structure, and can achieve rated power output capacity of 5KW to 15KW single-phase to 150KW three-phase four wire for frequency converters according to different applications.
For single-phase frequency converters, a silicon carbide high-frequency power factor correction boost rectifier circuit is used; For three-phase frequency converters, a silicon carbide full bridge PWM rectifier circuit is adopted; The purpose of achieving high input power factor and low input current harmonics in variable frequency converter power supplies.
The input power supply is rectified by an active PFC and outputs a DC bus voltage. The DC bus voltage is connected to a SIC high-frequency isolated bidirectional DC/DC inverter, and the input circuit and output circuit are electrically isolated through a high-frequency isolation transformer. And the high-frequency isolated DC/DC circuit is a bidirectional energy conversion circuit, which can achieve bidirectional automatic transmission of energy from input to output or from output to input. The other circuit is connected to the auxiliary power supply DC/DC isolation converter, providing various voltage auxiliary power supplies for the entire module. Multiple high-capacity supporting capacitors are connected in parallel to the DC bus,which not only achieves the filtering function of the DC bus, but also provides sufficient instantaneous power capacity for impulse loads.
This series of modular frequency converters not only adopt the latest high-frequency inverter circuit topology design and control algorithms, but also adopts multiple proprietary control technologies and manufacturing processes of our company that has continuously developed and optimized in the variable frequency converter industry for more than 20 years. These proprietary technologies include but are not limited to the following: "silicon carbide tube parallel drive and protection technology", "single-phase active PFC rectification technology", "three-phase PWM rectification technology", "SVPWM wave generation control technology", "instantaneous voltage waveform control technology", "wave by wave current limiting control technology", "unmanned adaptive synchronous parallel operation control technology", "power module hot swap technology" and other proprietary technologies and rigorous design and manufacturing processes of our company, Ensure that the quality performance of this series of modular frequency converter equipment reaches the highest level in the field in China.
Advantages:
Active PFC thyristor rectifier. The input harmonic current is small THDi ≤ 3%, the input power factor is high PF ≥ 0.99.
Using silicon carbide power switching devices to form a full bridge inverter or DC/DC converter. The switching frequency is high from 40KHz to 80KHz, with fast control speed and high accuracy. The output AC ripple is small, and the sine wave shape is extremely smooth.
Using high frequency isolation transformer inside, with small size and weight.
Due to the high switching frequency of inverter, with small size and weight, low heat generation of the inverter, the inverter achieves silent operation of the variable frequency converter power supply.
With standard modular design. Implement modular hot swapping function.
Each power module can have power capacity of up to 15KVA, and multiple power modules can be connected in parallel for expansion or redundant power supply based on the output power capacity of the variable frequency converters.
Specification: