Technical Specifications

Key Features

Dongfang Hitachi provides integrated solutions to meet customer’s needs on power quality control and management. We offer solutions including power quality data collection and analysis, system design, equipment selection & configuration, and system monitoring.

DHSTATCOM series, with the latest reactive power compensation technology, truly realizes the dynamic reactive power compensation. This electrical control equipment can provide dynamic reactive power support to the power system, filter out the harmonics, suppress voltage fluctuation and flicker, and correct the three phase unbalance.

Adopted multiple algorithms to eliminate harmonics up to 13^th order

Applied both Instantaneous and Discrete algorithms, DHSTATCOM series can be used for different load conditions. Its switching frequency is 5 kHz, and it can suppress harmonics up to 13^th order.

Adopted direct power control technology to compensate reactive power

Direct power control technology is applied to enable DHSTATCOM to generate or absorb reactive power as commanded. The commanded reactive power can be fixed (given by the grid scheduling for example), and it can also be instantaneous in the dynamic compensation system.

Adopted compensation control technology to balance three-phase voltages

Compensation control algorithms are applied to correct the unbalance of three-phase voltages. When there is large impedance in the system, the commanded reactive current of each phase is obtained using voltage amplitude closed-loop, and balancing three-phase voltages can be accomplished by controlling each of the three phases.

Adopted closed-loop voltage control technology to suppress voltage fluctuation

Closed-loop voltage control technology is applied in DHSTATCOM series to smooth out system voltage fluctuations caused by grid voltage variation or instantaneous change of the loads. The suppression rate on voltage flicker can reach to 5:1 or even higher.

Adopted modular design for ease of maintenance and system extension

DHSTATCOM series was designed with modular approach for ease of maintenance. Each module is controlled by a separate chip. In addition, the system includes RS485, DI, DO and other interfaces, which provides flexibility for system extension.

Applications

The applications of Low Voltage DHSTATCOM are mainly in manufacturing sector for controlling harmonic pollution, compensating reactive power, balancing phase voltages, and correcting voltage fluctuations and distortion.

The drive and control devices are essential equipment in the factories of automobile, photovoltaic, chemical, electronics etc. These devices usually adopt the six-pulse rectifier, which introduces very high harmonic content. The electroplating rectifier, tire rubber mixer machine, and tobacco extractor etc. also produce severe harmonics mainly at the order of 5th, 7th, 11th, and 13^th. Additionally, the harmonics pollution is worsen as the capacity of SCR based heating equipment in the precision manufacturing is getting bigger.

In the heavy manufacturing, the equipment such as crane, hoist, electric welding machine, rolling mill, and electric arc furnace etc., produce harmonics mainly below the 13^th order. Meanwhile the impact from the large loads leads to reactive power changes, and causes great voltage fluctuation. Electric welding machine and some furnaces use two-phase power supply, and introduce three-phase unbalance. 

Using DHSTATCOM can effectively solve above mentioned problems including harmonic pollution, voltage fluctuation and distortion. It can improve the power quality to ensure the stable operating environment of the equipment, reduce damage and failure rate, and save energy.