Known to provide resistance torque (power
running) when the AC power is loaded dynamometer state, will produce additional
power, so the power dynamometer test systems under different test environments,
the processing power of a key. Currently, on the dynamometer test bench power
handling in the following ways: achieving energy through common DC bus system
closed-loop feedback (such as transmission test bench, test bench torque
converter, etc.); using braking resistors consumption ( If the engine test bench, etc.); recovered by AFE
front-end energy, electricity will be generated without interfering feedback
network (such as engine test bench, etc.).
Choose a different form of energy treatment methods, subject to user laboratory management policies, test bench power input of the driver the choice of equipment, energy costs and effects processing unit; However, the actual situation of users, to provide users with appropriate processed form of economic power, is undoubtedly of great value to the user!
The first way: form a common DC bus
Common DC bus in the form of essence rectifier unit + N inverters.This is a clever use of all forms of load characteristics, the rational allocation and load electric power generation, to realize their own use of state power. Feedback on energy dynamometer DC bus power flow and no back grid, so there is no interference on the grid, the power line will not affect the operation of other equipment. Entire test rig has a good dynamic and static performance, no cooling equipment and cooling water, the test is simple and convenient, meet the energy requirements of environmental protection.
Electric Dynamometer vector converter
The second way: energy braking resistor box
Braking resistor box energy is a common way to power through the resistor box dynamometer power generated in the form of heat energy consumed, and its essence is: Drive + braking unit and braking resistor, four medium power exchanges Transmission in the quadrant can be widely applied. But the presence of the following disadvantages, one bad test environment impact on the environment, especially in the summer, there are high temperature resistance box, to be put to a special, and security measures; Second, due to the energy go to waste, so the cost of the user's test high, especially for heavy duty engine manufacturing and testing units, the rational use of the resources, users can bring huge gains (by the following third way).
Electric Dynamometer Braking resistors
The third way: Grid Energy Recovery
This method can effectively use hand dynamometer power generated electricity, on the other hand sine wave current feedback approach can reduce input current harmonics to less than 5 percent, to keep the network side power factor unity power factor, better energy efficiency effect, with active reactive power compensation, harmonic elimination initiative, online regulator function. Without the input and DC reactor nor will it interfere with the grid, enough to keep the dynamometer torque output at low or fluctuating mains voltage and maintain a large load stable, drift, with excellent dynamic characteristics.Can eliminate electromagnetic interference and harmonic interference inverter to the instrument.
Energy recovery is the essence of the grid: Drive + AFE energy feedback unit, you can achieve a symmetrical four-quadrant characteristics.AFE active front-end consisting of a three-phase IGBT bridge structure, to achieve two-way flow between the grid and the inverter DC bus energy.Since the initiative after the AFE abandoned behind the front fixed bridge diode rectifier mode, either at work or in the back under state rectifier are switching state by switching IGBT to achieve the corresponding functions, so use the AFE active front, both inrectification or in the feedback condition, the inverter side current harmonics are rarely sine wave, power factor close to 1, which greatly reduces the interference on the grid.At the same time the AFE inverter using active front, because the front two-way flow of energy can be achieved, and therefore can be applied to a variety of four-quadrant operation requires motor occasions, as well as the motor drive system in a variety of inertial load.
Meanwhile, AFE rectifier power feedback unit using purification filters and line reactors and IGBT power device technology, AFE grid system makes no harmonics, so the grid current is relatively small, and therefore the size of the network side of the element than normally used by the systemsmall element size, higher energy conversion efficiency.The same power inverter unit generates harmonics AFE rectifier than other much smaller.Not cause serious harmonic pollution on plant grid, is not affected by fluctuations in the power grid, with excellent dynamic characteristics.Therefore, AFE rectifier feedback unit has irreplaceable advantages in this regard.