## 1 Introduction  
With the advancement of the latest high-performance rare-earth magnetic materials, permanent magnet (PM) motors are becoming increasingly popular in various applications ranging from electric and hybrid electric vehicles, and renewable energy systems including wind generators, electric aircraft, and industrial drives. In general, PM motors have two significant advantages. The one is its compact size, and the other is high power density. Due to these advantages, many studies have been conducted on the PM-type vernier motor as a direct-drive motor without a reducer. They provide maintenance-free operation in various applications. In particular, PM plays an essential role for the motor and significantly contributes to improving performance. A stronger magnet force of the magnet enables the motor's higher performance, resulting in the most high-performance motors generally using rare-earth magnets. However, these magnets have two crucial disadvantages: the potential restrictions on the supply of rare-earth magnetic materials, the sharp fluctuation in price, and the environmental pollution crisis [1, 2, 3]. Improving the motor's torque density is the most critical way to reduce the use of PMs significantly. There is also a way to use a high-torque vernier motor at low speeds [4, 5, 6, 7, 8, 9, 10]. A permanent magnet vernier machine with concentrated windings can offer high torque capability at low speed while reducing the number of slots and thus copper loss. In order to improve the power density, the vernier reluctance machine incorporates PMs to provide the excitation, thus becoming the PM vernier (PMV) machine, which includes the single-excitation PMV (SE-PMV)-type [6; 8] and the dual-excitation (DE-PMV)-type [7]. The motor designs with PMs on the stator side have been proposed to extend the operational speed range and to decrease the inductance of the electromagnet. However, for the electromagnets, when a three-phase alternating current is applied to the coil at the constant magnetic poles, a short magnetic flux is generated, and there is less increase in performance compared to when a permanent magnet is added to the stator electromagnet because the permanent magnets are fixed. [PERSON] presented a surface permanent magnet (SPM)-type vernier motor. [PERSON] presented a comparative study of a double-sided toroidal-winding linear PM vernier machine. Among these vernier motors, the design with PMs on both a rotor and a stator, that is, a double half vernier motor, has the highest power density. In particular, we already studied the design with PMs on both the rotor and stator sides and presented a double half permanent magnet (DHPM)-type vernier motor that has a high power density among the other vernier motors [11]. In a previous study [11], we presented the research results that can decrease the number of permanent magnets required in the motor by improving the torque characteristics using a DH vernier motor as a direct-drive system. The research proposed that a new half vernier PM motor is promising as a direct-drive motor. This paper focuses on this point and further improved the torque performance and energy density. It presents a new DHPM vernier motor in which the permanent magnet on the stator is replaced by a salient pole and a saddle coil. As a result, the torque was increased to 4.92 N\(\cdot\)m in the proposed motor under the same conditions, compared to 3.85 N\(\cdot\)m in its predecessor presented in [11]. The motor's space volume ratio was also improved by 12% compared to the predecessor. In addition, we use finite element analysis to verify the improved characteristics for torque and energy density of the motor in this paper. The remainder of this paper is structured as follows: Section 2 discusses works related to the structure and principle of DHPM-type vernier motor. Next, Section 3 shows the performance comparison between the predecessor and the proposed DHPM-type vernier motor. Section 4 presents the comparison of specifications, and it also presents the results and discussion.