Energy Accumulator Emulator with Predictive Pulse Pattern Control
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Solution Overview
Problem
Existing energy storage emulators face limitations in dynamics and flexibility due to the restricted sampling rate caused by pulse width modulation (PWM) in DC/DC converters, which hinders quick reaction to load disturbances and transient switching operations.
Innovation Solution
The implementation of a Predictive Pulse Pattern Control (PPPC) system, which combines an outer voltage regulator with an inner PPPC unit, allowing for variable switching times and pulse patterns to control the power switches independently of a fixed sampling rate, thereby enhancing the dynamics and flexibility of output voltage regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If PWM is used to control the DC/DC converter, then the control structure is simple and easy to implement, but the sampling rate is limited by switching frequency and switching losses, resulting in poor dynamics and slow response to disturbances
Solution Approach 1:
The patent applies dynamics principle by making the switching times variable rather than fixed to a sampling grid. The PPPC unit calculates optimal switching times continuously based on current state, allowing the system to adapt dynamically to load changes and disturbances, thereby improving response speed while maintaining control simplicity
Solution Approach 2:
The patent changes the parameter of switching time from being constrained by fixed sampling intervals to being continuously variable. By calculating switching times based on instantaneous system state and predicting future states, the system achieves faster response without increasing switching frequency or complexity
2Speed
If the sampling rate is increased through oversampling, then the response dynamics improve, but the system becomes impractical due to severe restrictions on switching frequency and losses
Solution Approach 1:
The patent applies preliminary action by predicting future system states and calculating optimal switching times in advance, before disturbances occur. The PPPC unit uses predictive models to determine the best switching moments, allowing the system to respond proactively to anticipated changes without increasing actual switching frequency, thus avoiding additional switching losses
3Device complexity
If PWM with fixed sampling rate is used, then the control structure remains simple, but the system cannot react quickly enough to load disturbances and transient switching operations
Solution Approach 1:
The patent applies feedback principle by continuously monitoring system state variables (currents, voltages) and using this information to calculate optimal switching times. The PPPC unit incorporates feedback from the actual system state to adjust switching moments, ensuring reliable transient response while keeping the control structure relatively simple through direct calculation rather than complex iterative algorithms
Data Source
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AI summary
In order to specify an energy accumulator emulator having a dynamically and flexibly regulatable output voltage (v2), a DC-to-DC converter (1) having a number of circuit breakers (So1, So2, So3, So4, Su1, Su2, Su3, Su4), and a control unit (2) which is configured to calculate a reference current (i2R) from electrical variables (iL1, iL2, iL3, iL v2, iL) of the DC-to-DC converter, are provided according to the invention. A battery model (3) is connected to the control unit (2) and is configured to obtain and process the reference current (i2R) and to provide the control unit (2) with the reference voltage (V2R). The control unit (2) contains a voltage regulator (VR) which processes the reference voltage (v2R) and regulates a current (i1*), on the basis of which the control unit (2) controls the circuit breakers (So1, So2, So3, So4, Su1, Su2, Su3, Su4) via switching pulses (S1, S2, S3, S4) in order to regulate the output voltage (v2). A PPPC unit is connected to the voltage regulator (VR) and comprises a PPPC regulator (201), a pulse generator (202) and a selection unit (200) which provides a number of pulse patterns (A, B, C, D). The PPPC regulator (201) is configured to select a pulse pattern (A, B, C, D) of the selection unit (200) on the basis of the current (i1*) predefined by the voltage regulator (VR) and to control the circuit breakers (So1, So2, So3, So4, Su1, Su2, Su3, Su4) via the pulse generator (202) by means of switching pulses (S1, S2, S3, S4) according to this pulse pattern (A, B, C, D).