Xin Chen

With the increasing penetration of converter-interfaced renewable energy sources, converter-dominated power systems (CDPS) have become increasingly vulnerable to wideband oscillations. Impedance-shaping control has been recognized as an effective solution for oscillation mitigation. However, existing impedance-shaping approaches offer suffer from inconsistent design objectives and complicated parameter tuning requirements, which limit their applicability in practical CDPS. To address these issues, this paper proposes a broadband admittance-shaping control strategy incorporating a fundamental-frequency reactance coefficient regulation mechanism to improve compatibility among diverse converter types. Furthermore, a coordinated admittance-shaping control scheme is developed for converters with dominant oscillatory dynamics. Specifically, distributed coordination among multiple converters is achieved through online adjustment of admittance-shaping coefficients according to oscillation participation factors, oscillation conditions, and converter capacities. Hardware-in-the-loop (HIL) experimental results validate the theoretical analysis and demonstrate the effectiveness of the proposed strategy in enhancing system stability and suppressing sideband oscillations.

Subsynchronous resonance (SSR) is a critical stability concern in series-compensated wind farm systems employing doubly-fed induction generators (DFIGs). To investigate the root cause of SSR, this paper introduces an equivalent damping factor that quantitatively evaluates system damping and elucidates the formation mechanism of negative damping. Based on this, a corresponding stability criterion is derived to facilitate rapid stability assessment. To mitigate SSR, a novel suppression method is proposed, in which a full compensation design concept for negative damping is adopted, and the additional control parameters are determined based on the damping cancellation principle. Furthermore, an adaptive control strategy is developed to accommodate varying operating conditions. Hardware-in-the-loop (HIL) experimental results validate the effectiveness of the proposed strategy, demonstrating its ability to extend the positive damping region and robustly suppress SSR under diverse operating scenarios.

Due to the presence of large DC-link capacitors in more-electric aircraft (MEA) electric power system (EPS), the brushless synchronous DC generator (BSDG) often fails to meet the dynamic performance requirements of the DC-link voltage under abrupt load changes. As a widely used optimization method, the load current feedforward (LCF) control estimates the required field current under various operating conditions and superimposes it onto the voltage loop output, thereby accelerating its response. However, as the parameters of BSDG are susceptible to variations, the compensated field current may significantly deviate from the actual requirement. To achieve a robust dynamic performance, this paper develops an accurate model of the BSDG’s field current that accounts for the coupling relationship between the DC-link voltage and the load current, as well as the effects of operational parameters and parameter drift. Based on this model, a dynamic field current tracking (DFCT) strategy incorporating full-variable voltage and current feedforward is proposed. This method ensures optimized dynamic performance even under parameter drift conditions. Finally, comparative experiments conducted on a 1 kW brushless generator platform demonstrate the superior dynamic performance of the proposed DFCT method compared with conventional LCF control.

The escalating integration of constant power loads in advanced DC aircraft electrical power systems introduces critical stability challenges when interfacing with DC three stage brushless generator (DC-TSBG). Traditional capacitance augmentation approaches are high cost under aviation-grade weight and power density constraints. This paper proposes a parameter-independent adaptive stabilization methodology for diode-rectifier-based DC-TSBG systems, addressing both self-stability and source-load interactive stability. Firstly, an enhanced impedance modeling framework capturing the wide frequency-domain characteristics of DC-TSBG is derived, and the stability analysis of a system consisting of DC-TSBG and DC/DC converters is presented. Furthermore, a general adaptive stabilization method of DC-TSBG is proposed, which enables a stable operation of the aircraft power system with a diode rectifier. Experimental verification confirms the precision of the impedance model and the effectiveness of the proposed adaptive stabilization technique.

Increased penetration of power converters within electrical power systems frequently induces resonance issues, which can often be mitigated by reshaping the output impedance of renewable energy sources (RES). From the perspective of feasibility and cost‐effectiveness, the energy storage converter (ESC), which is already integrated into most newly built RESs, is a preferred device for impedance shaping to enhance system stability. This paper proposes an impedance matching control method for a grid‐forming energy storage converter (GFM‐ESC) to enhance system damping and improve overall stability. The proposed method modifies the conventional grid‐forming (GFM) control structure by introducing an impedance matching loop in the stationary (αβ) reference frame. This additional loop enhances the inherent damping capability of the GFM‐ESC, thereby improving the overall small‐signal stability of the system. Furthermore, an impedance matching principle based on the identification of dominant oscillatory frequency bands is employed to develop a systematic impedance design methodology. An 18‐kVA RES prototype, comprising a 3‐kVA ESC and a 15‐kVA grid‐connected converter (GCC), is built and tested to validate the effectiveness of the proposed control strategy.

Based on the substation outdoor box cabinet in the operation process, which is prone to condensation and overheating, this paper designs a temperature and humidity control device for outdoor box cabinet of substation based on STM32 micro-controller. The device uses STM32 as the main control unit, and uses DHT 11 temperature and humidity sensor to detect the temperature and humidity of the box cabinet, and compare the threshold value to judge the temperature and humidity in the box cabinet and control the heater and fan to effectively drive moisture and heat.

The dynamic performance of the DC bus significantly influences the impedance characteristics of MMC and the system stability in a high-voltage direct current system. However, most of the existing MMC-HVDC system stability research simplifies the DC side as an ideal voltage source and ignores the impacts of voltage feedforward control, which affects the accuracy and practicability of stability analysis. In this paper, a sequence impedance model considering both DC voltage control and voltage feedforward control is developed, and the necessity of considering DC control and voltage feedforward control for MMC-HVDC stability analysis is illustrated. Then, the impact of control parameters on MMC-HVDC impedance is discussed, and the boundary conditions of control parameters are also derived. Finally, a method of control parameters design and impedance optimization for MMC-HVDC based on the stability boundary is proposed. Compared to the traditional optimization method, the system stability is further improved by the impedance optimization method proposed this paper.

With the growth of economic and social demand for electricity, the power system has gradually evolved into a complex network containing a high proportion of renewable generators and large-scale electrical devices

Sub and super-synchronous resonance problems caused by the increasing penetration of wind energy in the grid usually can be solved by reshaping the impedance of wind farms. Considering the feasibility and economics, the static synchronous compensator (STATCOM), which is already part of the wind farm in certain regions, becomes a preferred option for impedance shaping to improve the system stability. However, due to the difference between the application object and the application scenario, the control schemes for impedance shaping that widely used in the two-level voltage source converter are difficult to apply directly to the MMC-based STATCOM to solve the resonance problems in the practical wind farm. Therefore, in this article, a broadband impedance shaping control scheme for MMC-based STATCOM is proposed to generate an active parallel impedance, thus reshaping the impedance characteristics of the wind farm over the sub and super-synchronous frequencies for enhancing the system stability. Then, a passivity-based design method for this impedance is developed to ensure that the proposed control can provide sufficient damping at the desired frequency. With this broadband impedance shaping control scheme, the STATCOM can effectively suppress resonance in the wind farm under various operation conditions, which is confirmed by the hardware-in-the-loop experimental results.