太危险，最好别试

请问有何作用？

怎会没有用?

to roy:将直流母线并联的意图何在？节能？省制动单元？有危险，建议别用，您可以选用共用整流单元类型的直流供电变频器，不仅节能，省制动单元，还省整流单元，只是这样的产品不大好买，可能也有其他方面的缺点，望其他仁兄指教！

ACS 600 Common DC Bus Description Voltage source inverters use a DC link between the output of the diode bridge rectifier and the input to the inverter section. The DC link also includes the capacitors that further smooth the resultant DC voltage and provide a low impedance source of energy. This document refers to the DC link as the DC bus. ACS 600 Common DC Bus is a system configuration in which individual DC buses of several ACS 600 drives are tied together to form a common DC bus structure. This configuration provides a path for power flow between drives at the DC bus level. It is intended for application on small systems that require simultaneous motoring (power sinking) of some sections and regenerating (power sourcing) of other sections. An example is a simple wind / unwind system. Total system losses under steady state conditions are normally such that motoring power required is more than the regenerative power available. Therefore, the Common DC Bus configuration typically allows steady state system operation with the common DC chopper inactive. A common DC chopper is, nonetheless, required for those periods of system operation when regenerative power exceeds motoring power (i.e. when the entire system is rapidly decelerated). The configuration dramatically improves overall system efficiency as compared to configurations that require braking choppers to absorb all regenerative energy. In addition it usually results in reduced size requirements for the braking chopper and the braking resistor. Another intended use for the ACS 600 Common DC Bus is to provide a configuration that requires only one common braking chopper to absorb power from multiple related drives. In applications of this type the ability of the common DC bus to pass power between drives is secondary in importance. Of primary consequence is the configuration’s capability to absorb power from multiple drives with a single braking chopper. This is normally a significantly more cost effective approach then the alternative of supplying individual braking choppers and resistors for each drive. The required braking energy should be calculated by an application engineer and the braking chopper and the resistors are selected according to the manual Installation and start-up Guide NBRA-6xx Braking Choppers. Scope The Common DC Bus configuration may be applied to all 400 Vac and 500 Vac ACS 600 drives. (See Table II for specific drive part number listing.) 230 Vac and 690 Vac ACS 600 configurations are not available. This guideline covers only ACS 600 drives. This guideline is not intended to cover other types or models of PWM drives or a mixture of ACS 600 drives with other types or models of PWM drives. General Restrictions The following general restrictions apply to all configurations: 1. All drives must be fed from a common AC feed. 2. All inverters must be sized based on the heavy duty Ihd current rating. Overload is limited to 1.1´ Ihd for 1 minute. Note that this limitation is more severe than that normally applied when using the heavy duty rating. 3. Standard ACS 600 earth fault protection can’t be used. If earth fault protection is required it must be implemented at the main AC bus level that feeds all drives. 4. The application must be such that abnormal shutdowns will not result in a personnel safety or equipment hazard condition. The application engineer is responsible for this determination. 5. The maximum number of the drives is three (3). 6. Internal braking choppers cannot be used.

楼上能不能再给翻译一下。