64results about How to "Enable accurate simulation" patented technology

The invention relates to a hydroelectric generating set speed regulation control simulation method and system. The system includes a RTDS real-time simulation apparatus, a frequency-testing unit, a water turbine governor, a water diversion system and a water turbine simulation apparatus. A water diversion pipeline water hammer effect model is established to simulate water diversion pipeline water hammer effects, an actual water turbine governor is subject to parameter and structure identification so as to establish a water turbine governor RTDS model which accords to actual operation mode and control mode. The simulation level of the governor is increased due to the RTDS model. Precise simulation of the characteristics of frequencies of the hydroelectric generating set is realized, and simulation precision is increased.

The invention discloses an evaluation method based on the influence of the shared memory accompanying the program group on the program execution time. Based on the given program to be tested, the program execution mode and the characteristics of the hardware platform, the impact of the shared memory on the program in the multi-core embedded system is evaluated. The impact of time, the steps are as follows: S1, build a simulation platform based on the given execution mode and hardware platform characteristics, S2, execute the program to be tested and the designed accompanying program group under the given execution mode, and obtain the execution time data, S3. Using the curve fitting method to obtain the fitting curve of the data, and through the test of the entire accompanying program group, sum up the influence of different accompanying programs on the execution time of the test program. This evaluation method achieves accurate simulation of actual application scenarios through the construction of the experimental platform and the setting of the program execution mode. On the simulation platform, the method uses a set of companion programs that cover a wide range of memory access patterns and are able to cover most real-world implementations.

The invention discloses an MMC flexible direct-current system. The MMC flexible direct-current system comprises a first converter station and a second converter station, wherein the first converter station and the second converter station are connected through a direct-current circuit and each comprise an alternating-current system, a main circuit breaker, a transformer and multiple bridge arms, each alternating-current system, the corresponding main circuit breaker and the corresponding transformer are sequentially connected in series, every two corresponding bridge arms are connected in series to form a phase of bridge arms, the number of the phases of the bridge arms is three, and the phases of bridge arms are connected in parallel and then are connected with the transformers in series; each bridge arm comprises a bridge arm reactor and a valve bank which are connected in series, each valve bank comprises multiple sub-modules, in the open circuit state, the sub-modules are equivalent to a series circuit of a resistor and a capacitor, and in the short circuit state, the sub-modules are equivalent to an inductive circuit. During real-time digital simulation, inversion does not need to be conducted on an admittance matrix again, in this way, a large amount of calculation time can be saved, the real-time simulation step size is reduced to smaller than several microseconds according to requirements, and accurate simulation of the MMC flexible direct-current system is achieved.